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Hoekom kan anafilakse tot die dood lei?

Hoekom kan anafilakse tot die dood lei?


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Hoekom kan die immuunstelsel sy gasheer doodmaak?

Dit is altyd beter om net die insekgif, of grondboontjieproteïen ens. op te neem eerder om die gasheer dood te maak deur die asemhaling te voorkom.

Is dit net 'n moderne simptoom of moes mense altyd die dood van anafilakse na 'n inseksteek vrees?


Anafilakse: 'n Oorweldigende allergiese reaksie

Sarah Lyman het geen rede gehad om bekommerd te wees toe haar man John die huis verlaat het vir 'n draf na middagete nie: hy het na sy gewone gesonde self gelyk. Twintig minute later het sy gehoor dat hy langs die pad ineengestort het - baklei om asem. By die hospitaal het sy uitgevind dat die oorsaak anafilakse was (ook genoem anafilaktiese skok of allergiese skok), waarskynlik veroorsaak deur die kreefslaai wat hulle vir middagete geëet het. Gelukkig is John betyds behandel en het dit oorleef. Dat hy allergies was vir skulpvis was vir hom nuus.

Anafilakse is 'n ernstige en soms lewensgevaarlike reaksie wat binne 'n uur - en soms binne minute of selfs sekondes - kan ontwikkel na blootstelling aan 'n allergeen, 'n stof waarvoor 'n individu se immuunstelsel sensitief geraak het. Baie allergene kan anafilakse aanraak, insluitend voedsel, medikasie en inseksteke (sien "Anafilakse-snellers"). In John Lyman se geval het sy postprandiale draf waarskynlik 'n rol gespeel: anafilakse word soms veroorsaak deur aërobiese aktiwiteit soos draf - veral na die inname van allergene kosse of medikasie. Soms is die oorsaak onbekend.

Anafilakse snellers

Voorbeelde/bronne

Grondbone, boomneute (okkerneute, pekanneute, amandels, kasjoeneute), skulpvis (kreef, garnale, krap, mossels, mossels, oesters), vis, melk, eiers. Voedselbymiddels, insluitend speserye en groentegom.

Insekte uit die orde Hymenoptera, wat insluit Vespidae (perdebye, geel baadjies, wespe), Apidae (hommelbye, heuningbye), en Formicidae (vuurmiere).

Antibiotika (veral dié in die penisillien- en kefalosporiengroepe) niesteroïdale anti-inflammatoriese middels soos ibuprofen, naproxen en aspirien, sommige kontrasmiddels (kleurstowwe) wat gebruik word in diagnostiese x-strale en skanderings chemoterapie-middels* (platienmiddels, taksane, doksorubisien) opiate monoklonale teenliggaampies.

Kan gevind word in mediese en tandheelkundige voorrade, insluitend sommige weggooibare handskoene, kateters, bloeddrukmanchette, stetoskope, brille en tandheelkundige damme en in baie ander produkte, insluitend kondome, diafragmas, ballonne, sporttoerusting, skottelgoedwashandskoene, rubberbande, uitveërs .+

Ingespuite narkosemiddels soos prokaïen of lidokaïen neuromuskulêre blokkeringsmiddels wat tydens narkose gebruik word, soos vekuronium en suksametonium seminale vloeistof.

*Teen die sewende ronde chemoterapie ontwikkel soveel as een vierde van kankerpasiënte allergiese reaksies, insluitend anafilakse.

**Mense met latexallergie is dikwels ook allergies vir sekere kosse, soos piesangs, avokado's, kiwi's en kastaiings.

+Bronne van latexvrye verbruikers- en mediese produkte word gelys op die webwerf van die American Latex Allergy Association, www.latexallergyresources.org/links/products.cfm.

Anafilakse vind plaas wanneer allergeen-sensitiewe selle in bloed en ander weefsels groot hoeveelhede histamien en ander inflammasie-veroorsakende chemikalieë vrystel. Terwyl die meeste allergiese reaksies slegs een fisiologiese stelsel behels (byvoorbeeld die boonste lugweg of die vel), is anafilakse 'n kaskadereaksie wat verskeie stelsels behels. (Sien "Tekens en simptome van anafilakse in aangetaste liggaamstelsels," hieronder.)

Simptome is veranderlik, maar kan spoel, jeuk, neusverstopping, hyg, moeilike asemhaling en swelling van die keel en tong insluit, wat soms gepaard gaan met naarheid, braking en diarree. Bloeddruk kan vinnig daal, wat flouheid veroorsaak. 'n Onmiddellike inspuiting van epinefrien (adrenalien) kan die waterval stop, wat andersins tot floute, skok en selfs die dood kan lei.

Anafilakse is waarskynlik meer algemeen as wat een keer gedink is. Dit word op baie verskillende plekke behandel - hospitale, noodkamers en klinici se kantore, sowel as nie-mediese instellings - en gesondheidsowerhede hou nie tred met gevalle nie, so daar is geen enkele bron van data daaroor nie. Ook, omdat die simptome so veranderlik is, kan anafilakse verwar word met iets anders, soos 'n asma-aanval, 'n paniekaanval, selfs 'n derminfeksie of voedselvergiftiging. En mense met ligte simptome mag nie mediese hulp soek nie. 'N 2006-studie deur Harvard Mediese Skool-navorsers het bewyse gevind dat anafilakse grootliks ondergerapporteer word as die oorsaak van ernstige allergiese reaksies wat in noodkamers behandel word - 'n probleem, want behoorlike diagnose is die eerste stap om nog 'n anafilaktiese reaksie te voorkom.

In 2008 het 'n paneel wat deur die American College of Allergy, Asthma, and Immunology byeengeroep is, data van 'n aantal bronne nagegaan en tot die gevolgtrekking gekom dat anafilakse 1% tot 2% van die bevolking affekteer, en die frekwensie neem toe (Huidige mening in Allergie en Kliniese Immunologie, Augustus 2008). Die studie het ook bevind dat risiko hoër is by vroue as by mans. (Volgens die paneel dui laboratoriumbevindinge daarop dat die vroulike hormoon progesteroon die liggaam se reaksie op 'n allergeen 'n hupstoot kan gee.) Daar word vermoed dat noodlottige anafilakse skaars is, maar onderrapportering kan ook hier 'n probleem wees, want die reaksie kan oor die hoof gesien word as die oorsaak van dood by mense wat asma, longsiekte of kardiovaskulêre siekte het.

Enigiemand wat anafilakse gehad het, loop die risiko vir verdere sulke reaksies in die toekoms, so dit is belangrik om die snellers te identifiseer en te vermy en om voor te berei vir enige toevallige blootstelling. Dit beteken om te alle tye self-inspuitbare epinefrien byderhand te hê en te weet hoe om dit te gebruik.

Tekens en simptome van anafilakse in aangetaste liggaamstelsels

Tekens en simptome

Slymhuid (vel en mukosale areas)

Warmte en blosing van die vel, korwe, intense jeuk, swelling onder die oppervlak van die vel (angioedeem), maselsagtige uitslag, hare wat regop staan ​​(piloereksie), jeukerige kopvel. Jeuk of tinteling van die lippe, tong, of dak van die mond. Swelling van die lippe, tong of uvula. Metaal smaak. Jeuk, swelling en rooiheid rondom die oë, skeur. Jeuk in die oorkanale.

Loopneus, opeenhoping, nies. Strengheid in die keel (moontlik gepaardgaande met probleme om te sluk), verswakte spraak, heesheid. Kortasem, moeilike asemhaling, benoudheid in die bors, diep hoes, hyg, belemmerde lugvloei.

Naarheid, krampe, braking, diarree.

Borspyn, hartkloppings, abnormale hartritme, lae bloeddruk (moontlik gepaardgaande met tonnelvisie en moeilike gehoor), bleekheid, flouheid of duiseligheid, verlies van bewussyn.

Angs, gevoel van naderende straf, verwarring. Laer rugpyn by vroue (as gevolg van baarmoederkrampe).


Wat om te weet oor anafilakse

Anafilakse is 'n ernstige allergiese reaksie. Dit kan lei tot 'n potensieel dodelike toestand bekend as anafilaktiese skok.

Elke jaar is daar 200 000 hospitaalbesoeke weens voedselallergieë in die Verenigde State, volgens die Asma- en Allergiestigting van Amerika (AAFA).

Mense het ook algemeen allergiese reaksies op medikasie en inseksteke.

Die AAFA rapporteer dat meer as 50 miljoen mense in die VSA elke jaar 'n allergiese reaksie het en dat allergieë die sesde grootste oorsaak van chroniese siektes in die land is.

Hieronder beskryf ons hoe 'n ernstige allergiese reaksie - 'n toestand genaamd anafilakse - voel en wat om te doen as dit gebeur. Ons ondersoek ook die oorsake en wat in die liggaam aangaan tydens hierdie reaksie.

Anafilakse vind plaas wanneer die liggaam op 'n vreemde stof reageer asof dit 'n ernstige bedreiging vir die gesondheid is.

Die mees algemene snellers vir hierdie reaksies is medikasie, kos en inseksteke.

Sommige kosse wat dikwels allergiese reaksies veroorsaak, sluit in:

  • melk
  • eiers
  • vis
  • skaaldier skulpvis
  • koring
  • soja
  • grondboontjies
  • boom neute

Enige stof wat 'n allergiese reaksie veroorsaak, word 'n allergeen genoem. Vir sommige mense kan selfs minimale blootstelling aan spore van 'n allergeen 'n ernstige reaksie veroorsaak.

In sy reaksie op 'n allergeen, produseer die liggaam groot hoeveelhede histamien - 'n seinmolekule wat 'n inflammatoriese reaksie kan veroorsaak.

Hierdie reaksie kan lei tot:

  • verwyding van die bloedvate
  • 'n skielike daling in bloeddruk
  • verlies van bewussyn
  • skok

In 'n persoon wat anafilakse ervaar, word die lugweë dikwels nou, wat asemhaling moeilik maak.

Daarbenewens kan die bloedvate lek, wat edeem veroorsaak, 'n tipe swelling wat voortspruit uit die ophoping van vloeistof.

Die reaksie kan onmiddellik na kontak met die allergeen of binne ure na kontak plaasvind. Baie af en toe gebeur dit dae later.

Die simptome van anafilakse kan aandui dat dringende mediese aandag nodig is.

Elke individu se spesifieke simptome sal afhang van die tipe allergie en die sneller, maar dit kan die volgende insluit:

  • neusverstopping
  • 'n jeukerige mond of keel
  • 'n vol, swaar gevoel in die tong
  • probleme om te sluk of 'n gevoel dat iets aan die tong of keel vassit
  • n hoes
  • 'n hees stem
  • hyg
  • kortasem en benoudheid in die keel
  • moeilike asemhaling
  • borspyn
  • maagpyn en krampe
  • naarheid en opgooi
  • swelling en jeuk van die vel, wat warm en rooi kan wees, met korwe of 'n ander uitslag en 'n gevoel van naderende straf
  • swelling van die voete, hande, lippe, oë en soms die geslagsdele
  • lae bloeddruk en swak sirkulasie, wat lei tot ligblou vel
  • 'n lae polsslag, duiseligheid of flouheid
  • skok
  • verlies van bewussyn

Die persoon kan ook jeukerige, rooi, waterige oë, hoofpyn en krampe in die baarmoeder hê. Hulle kan 'n metaalsmaak in hul mond hê.

Erge asemhalingsprobleme, 'n aansienlike daling in bloeddruk, of albei kan tot skok lei, wat dodelik kan wees.

Enigiemand wat 'n ernstige allergiese reaksie ervaar, benodig dringende mediese aandag.

Noodhulp vir anafilakse sluit die volgende stappe in:

  1. Verwyder die allergeen, indien moontlik, en ontbied noodhulp.
  2. Hou die persoon koel en maak enige streng klere los.
  3. As hulle flou voel, laat hulle sit, leun of plat lê.
  4. Vra of die persoon 'n geskiedenis van allergiese reaksies het.
  5. Help hulle om enige allergiemedikasie wat hulle dra, toe te dien.
  6. Stel die persoon gerus en bly by hulle totdat noodhulp opdaag.

As die persoon 'n geskiedenis van ernstige reaksies het, kan hulle 'n adrenalien, of epinefrien, inspuitstel dra. Dit kan 'n outo-inspuiter bevat, soos 'n EpiPen.

Die inspuiter sal 'n dosis epinefrien verskaf, 'n vorm van adrenalien.

Kenners beveel aan dat sommige mense met allergieë te alle tye twee inspuiters dra.

As 'n kind die medikasie benodig, kalmeer hulle eers en maak seker dat hulle stil is. Dit sal albei hande vry laat om die toestel te gebruik.

Wanneer 'n EpiPen-inspuiter gebruik word, is dit noodsaaklik om:

  1. Verwyder die pen uit die draagtas.
  2. Hou die inspuiter in een vuis vas, met die oranje punt na onder.
  3. Verwyder die blou veiligheidsvrystelling met die ander hand - in 'n reguit opwaartse beweging, sonder om te buig of sywaarts te draai.
  4. Swaai die hand wat die toestel na die kant toe dra en druk die oranje punt stewig teen die buitenste bobeen, teen 'n regte hoek met die been.
  5. Luister vir 'n klik terwyl die naald deur die oranje punt van die toestel kom en die dosis toedien.
  6. Hou die naald in plek vir ten minste 3 sekondes.

Nadat die dosis toegedien is, sal die oranje punt die naald bedek en die venster van die toestel sal geblokkeer word. As die naaldpunt nog sigbaar is, moenie die naald hergebruik nie.

Moet nooit die blou veiligheidsvrystelling met 'n duim afdraai nie - gebruik altyd twee hande om die inspuiter voor te berei.

As die veiligheidsvrystelling verkeerd verwyder word, kan dit veroorsaak dat die inspuiter sy inhoud te vroeg vrystel. Gevolglik mag daar geen medikasie in die toestel wees wanneer die persoon dit toedien nie.

Daar is verskillende tipes inspuiters. Alhoewel hulle oor die algemeen op dieselfde manier werk, kan die instruksies vir elke tipe effens anders wees.

Die skakels hieronder verskaf spesifieke instruksies vir verskillende inspuiters:

Terwyl jy vir hulp wag, maak seker dat die persoon kan asemhaal. Om asemhaling makliker te maak, moet die persoon regop sit en 'n bietjie vorentoe leun.

As hulle egter flou voel, moet hulle plat lê met hul bene omhoog.

As die persoon flou word, maak seker dat sy kop agteroor gekantel is en dat hy kan asemhaal.

Bly by die persoon en monitor hul toestand totdat 'n gesondheidswerker opdaag. Wanneer hulle dit doen, verduidelik, indien moontlik:

Indien moontlik, maak seker dat die allergeen wat veroorsaak, so ver as moontlik van die persoon af is. Dit moet hulle nie na die hospitaal vergesel nie.

As die persoon ophou asemhaal, dien kardiopulmonêre resussitasie (KPR) toe. Die borskompressies moet voortduur totdat professionele hulp opdaag.


Die patofisiologie van anafilakse

Anafilakse is 'n ernstige sistemiese hipersensitiwiteitsreaksie wat vinnig begin, gekenmerk deur lewensgevaarlike lugweg-, asemhalings- en/of sirkulasieprobleme en gewoonlik geassosieer met vel- en slymvliesveranderinge. Omdat dit by sommige persone veroorsaak kan word deur klein hoeveelhede antigeen (bv. sekere kosse of enkele inseksteke), kan anafilakse as die mees afwykende voorbeeld van 'n wanbalans tussen die koste en voordeel van 'n immuunrespons beskou word. Hierdie oorsig sal huidige begrip van die immunopatogenese en patofisiologie van anafilakse beskryf, met die fokus op die rolle van IgE- en IgG-teenliggaampies, immuuneffektorselle en bemiddelaars wat vermoedelik bydra tot voorbeelde van die afwyking. Bewyse van studies van anafilakse in menslike proefpersone sal bespreek word, sowel as insigte verkry uit ontledings van diermodelle, insluitend muise wat geneties gebrekkig is in die teenliggaampies, teenliggaamreseptore, effektorselle of mediators wat by anafilakse geïmpliseer is en muise wat "gehumaniseer" is. vir sommige van hierdie elemente. Ons hersien ook moontlike gasheerfaktore wat die voorkoms of erns van anafilakse kan beïnvloed. Ten slotte sal ons spekuleer oor anafilakse vanuit 'n evolusionêre perspektief en argumenteer dat, in die konteks van ernstige vergiftiging deur geleedpotiges of reptiele, anafilakse selfs 'n oorlewingsvoordeel kan bied.

Sleutelwoorde: Anafilakse IgE basofiele cysteiniel leukotriene epinefrien voedselallergie histamien mast selle plaatjie-aktiverende faktor urtikaria.

Kopiereg © 2017 Amerikaanse Akademie vir Allergie, Asma en Immunologie. Gepubliseer deur Elsevier Inc. Alle regte voorbehou.

Syfers

Figuur 1. Veelvuldige potensiële weë in teenliggaam-gemedieerde...

Figuur 1. Veelvuldige potensiële weë in teenliggaam-gemedieerde anafilakse

Figuur 2. Patofisiologiese veranderinge in anafilakse en...

Figuur 2. Patofisiologiese veranderinge in anafilakse en mediators wat by hierdie prosesse geïmpliseer is


Hoekom kan anafilakse tot die dood lei? - Biologie

Anafilakse (anna-fih-LACK-sis) is 'n ernstige allergiese reaksie wat vinnig begin en die dood kan veroorsaak.

Wat is die simptome van anafilakse?

Simptome behels gewoonlik meer as een orgaanstelsel (deel van die liggaam), soos die vel of mond, die longe, die hart en die ingewande. Sommige simptome sluit in:

  • Veluitslag, jeuk of korwe
  • Swelling van die lippe, tong of keel
  • Kortasem, moeilike asemhaling of hyg (fluitgeluid tydens asemhaling)
  • Duiseligheid en/of floute
  • Maagpyn, opgeblasenheid, braking of diarree
  • Baarmoederkrampe
  • Voel of iets aakligs gaan gebeur

Vra jou dokter vir 'n volledige lys van simptome en 'n anafilakse-aksieplan. Anafilakse moet dadelik behandel word om die beste kans op verbetering te bied en ernstige, potensieel lewensgevaarlike komplikasies te voorkom.

Wat is die behandeling vir anafilakse?

Epinefrien (ep-uh-NEF-rin) is die belangrikste behandeling wat beskikbaar is. Dra altyd twee epinefrien-outo-inspuiters sodat jy vinnig 'n reaksie kan behandel waar jy ook al is. (Kom meer te wete op ons verwante webwerf vir kinders met voedselallergieë: Epinefrien is die eerste behandelingslyn vir ernstige allergiese reaksies).

  • Spuit die medisyne dadelik in by die eerste teken van 'n anafilaktiese reaksie. Oorweeg dit om jou anafilakse-aksieplan saam met jou outo-inspuiters te dra.
  • Bel 911 om per ambulans na 'n hospitaal te gaan. Jy moet mediese sorg soek onmiddellik &ndash selfs al voel jy beter &ndash omdat simptome kan herhaal.
  • Jy benodig dalk ander behandelings, benewens epinefrien.

As jy dink jy het anafilakse, gebruik jou self-inspuitbare epinefrien en bel 911.
Moenie uitstel nie. Moenie antihistamiene in die plek van epinefrien neem nie. Epinefrien is die mees effektiewe behandeling vir anafilakse.

Wat veroorsaak anafilakse?

'n Allergie vind plaas wanneer die liggaam se immuunstelsel iets as skadelik sien en reageer. Jou immuunstelsel probeer om die sneller te verwyder of te isoleer. Die gevolg is simptome soos braking of swelling. Die mees algemene snellers van anafilakse is allergene. Medisyne, kosse, inseksteke en -byte, en latex veroorsaak meestal ernstige allergiese reaksies.

  • Medisyne is die hoofoorsaak by volwassenes
    Algemene skuldiges is penisillien en ander antibiotika, aspirien en aspirienverwante produkte en insulien.
  • Voedsel is die hoofoorsaak by kinders
    In die VSA is die mees algemene voedselallergieë grondboontjies, boomneute, skulpvis, vis, melk, eiers, soja en koring. Dit is die &ldquotop 8 allergene.&rdquo By kinders is die mees algemene voedselallergieë melk, eiers, grondboontjies, soja en koring. By volwassenes is die mees algemene voedselallergieë skulpvis, boomneute en grondboontjies.
  • Inseksteke en byte
    Stekende insekte soos bye, wespe, perdebye, geel baadjies en vuurmiere kan anafilakse veroorsaak. Sekere bosluisbyte kan veroorsaak dat 'n persoon ernstige allergiese reaksies op vleis ontwikkel. Byte van die "kissing gogga" en takbokvlieg veroorsaak ook 'n plaaslike allergiese reaksie.
  • Lateks
    Natuurlike rubberlatex kan 'n ligte velirritasie veroorsaak of dit kan 'n ernstige allergiese reaksie veroorsaak. Direkte kontak met latex items (latex handskoene, kondome en ballonne) kan 'n reaksie veroorsaak. As jy klein latexdeeltjies wat in die lug inasem, kan latexallergieë veroorsaak. Deur latexhandskoene aan en uit te trek, kan klein latexdeeltjies in die lug vrygestel word.
  • Fisiese aktiwiteit
    Oefening-geïnduseerde anafilakse is 'n seldsame allergiese reaksie wat plaasvind na strawwe fisiese aktiwiteit. Temperatuur, seisoenale veranderinge, dwelms, alkohol of die eet van sekere kosse voor oefening kan ko-faktore wees. Met ander woorde, beide oefening en hierdie ander faktor moet teenwoordig wees vir 'n persoon om die ernstige allergiese reaksie te hê.

Met behoorlike evaluering identifiseer allergiste die meeste oorsake van anafilakse. Sommige mense het allergiese reaksies sonder enige bekende blootstelling aan algemene allergene. As 'n allergis nie 'n sneller kan identifiseer nie, is die toestand idiopatiese anafilakse.

Hoe kan ek die verskil tussen anafilakse en asma vertel?

Mense met asma het ook dikwels allergieë. Dit stel hulle 'n groter risiko om anafilakse te ontwikkel, wat ook asemhalingsprobleme kan veroorsaak. Om dié rede is dit belangrik om jou asma goed te bestuur. Sommige van die simptome van 'n ernstige allergiese reaksie of 'n ernstige asma-aanval kan soortgelyk lyk. 'n Handige leidraad om dit van mekaar te onderskei, is dat anafilakse nou kan volg op die inname van 'n medikasie, die eet van 'n spesifieke kos, of om deur 'n insek gesteek of gebyt te word.


Hier is wat met jou liggaam gebeur tydens anafilakse

Volgens die Centers for Disease Control and Prevention raak allergieë meer as 50 miljoen Amerikaners elke jaar - en anafilakse, die ernstigste allergiese reaksie, affekteer ten minste 1,6 persent van die algemene bevolking [PDF]. Hier is die wetenskap van wat met die liggaam gebeur tydens anafilaktiese skok.

ALLERGEEN BLOOTSTELLING

In 'n persoon met allergieë identifiseer selle soms vreemde maar onskadelike stimuli as groot bedreigings. Waarom sommige mense allergies is vir sekere dinge terwyl ander nie is nie, is 'n raaisel wat die wetenskap nog nie opgelos het nie, maar ons weet hoe dit gebeur: deur 'n proses genaamd sensitisering.

Hier is hoe dit werk. Wanneer die liggaam 'n vreemde stof, ook 'n antigeen genoem, teëkom, lewer immuunstelselselle sommige van die stof se molekules aan T-helperselle wat in die limfknope woon. Daardie selle bring ook 'n tipe molekule saam wat 'n T-helpersel inlig dat dit tyd is om 'n immuunreaksie op te voer. Bekend as 'n kostimulerende molekule, is dit nodig om enige tipe immuunstelselreaksie waarby T-selle betrokke is, te aktiveer, of jy allergieë het of nie.

Om aan 'n antigeen blootgestel te word "primeer" 'n T-helpersel en verander dit in 'n Th2-sel. Geprimeerde Th2-selle stel proteïene genaamd interleukiene vry, wat twee dinge doen: Eerstens, hulle werk in wisselwerking met 'n ander tipe immuunsel genaamd B-selle om infeksiebestrydende teenliggaampies te produseer wat aan mastselle bind, wat chemiese deeltjies bevat wat hulle sal vrystel in die teenwoordigheid van 'n antigeen. Tweedens aktiveer die interleukiene eosinofiele, 'n tipe witbloedselle wat giftige stowwe afvoer om indringerselle (en soms gasheerselle) te vernietig. In hierdie proses identifiseer die immuunstelsel die "bedreiging" en ontplooi selle wat gereed is om dit te beveg. Die immuunstelsel se verhoogde vlak van bewustheid van en voorbereiding teen die antigeen herklassifiseer die stof as 'n allergeen - 'n aansienlik gevaarliker bedreiging.

Omdat 'n allergie eers ná hierdie proses ontwikkel, sal 'n persoon wat byvoorbeeld vir aarbeie allergies is, eers 'n reaksie ervaar die volgende keer as hulle iets eet wat aarbeie bevat. Nuwe allergieë kan enige tyd in jou lewe opduik.

'n Immuniteitstelsel teen allergieë is 'n bietjie soos 'n brein wat nie 'n stukkie pluis van 'n spinnekop kan onderskei nie: nie in staat om te ontspan nie, voortdurend op waak teen elke potensiële bedreiging. Na aanvanklike blootstelling is die mastselle wat tydens die sensitiseringsfase geaktiveer is steeds toegerus met allergeen-spesifieke teenliggaampies en bly gevegsgereed, bereid om onmiddellik te reageer sou 'n tweede blootstelling ooit plaasvind. As dit gebeur - en dit sal waarskynlik - hier is wat jy kan verwag om te gebeur.

ALLERGIESE REAKSIE

As twee of meer allergeenmolekules aan 'n sensitiewe mastsel bind, stel die mast inflammatoriese bemiddelaars vry wat 'n allergiese reaksie veroorsaak. Hierdie bemiddelaars sluit stowwe soos histamien en meer van die interleukiene in wat op hul beurt eosinofiele, Th2-selle en basofiele ('n ander tipe witbloedsel) aktiveer. In 'n nie-allergiese reaksie produseer bemiddelaars nuttige inflammasie wat infeksie voorkom en genesing begin - maar dieselfde simptome kan irriterend en selfs gevaarlik wees wanneer die immuunstelsel 'n andersins goedaardige allergeen aanval. Mastselle stel ook leukotriene vry, wat meer immuunselle na die area werf en die reaksie bespoedig. Dit lei tot wat Tina Sindher, navorser van Stanford Universiteit, 'n "kettingreaksie" van allergiese ontsteking noem.

Met die vrystelling van histamien kan jy beide brongiale sametrekking ervaar - wat dit moeiliker maak om asem te haal - en bloedvatverwyding. Laasgenoemde maak dit makliker vir bloed om na geaffekteerde gebiede te vloei, maar dit maak ook bloedvate meer deurlaatbaar, sodat bloed uit die bloedvatwande kan ontsnap en in die spasies tussen selle invloei en swelling en korwe veroorsaak.

Vir die meeste is hierdie simptome bloot ongemaklik, hulle kan so laat as agt tot 12 uur na aanvanklike blootstelling voorkom, lank nadat die allergeen weg is, en kan verlig word met 'n antihistamien soos Benadryl. Maar vir 'n persoon met ernstige allergieë kan 'n lewensgevaarlike allergiese reaksie binne minute voorkom: hul lugweë sal so saamtrek dat hulle nie kan asemhaal nie, en hul bloedvate sal nie kan saamtrek nie, wat kan lei tot 'n daling in 'n bloeddruk en verhoed dat are bloed terug na die hart kry. Die kombinasie van lugwegvernouing en bloedvatverwyding kan dit vir die liggaam onmoontlik maak om genoeg suurstof aan groot organe te verskaf—dit is anafilaktiese skok.

Die enigste manier om anafilakse in sy spore te stop, is met epinefrien, meer algemeen bekend as adrenalien. Adrenalien is 'n hormoon wat natuurlik deur die byniere geproduseer word om die "veg of vlug"-reaksie in noodsituasies te help genereer. Dit werk deur sekere bloedvate te vernou, bloeddruk te verhoog en lugweë te verslap, wat al die reaksies wat deur histamiene geproduseer word, teenwerk.

Volgens Sindher is dit belangrik om epinefrien dadelik te gebruik as jy 'n risiko vir anafilaktiese skok het. "Daar is 'n algemene oortuiging daar buite dat epinefrien slegs in die ergste scenario gebruik moet word," sê sy aan Mental Floss. "Trouens, die meeste van die komplikasies wat ons in voedselallergiese reaksies sien, is te wyte aan vertraagde gebruik in Epi. Antihistamiene kan nuttig wees om die simptome van jeuk en kongestie te behandel, maar dit help nie om ’n allergiese reaksie te stop nie.”

DIE TOEKOMS VAN ALLERGIE BEHANDELING

Navorsers soos Sindher probeer steeds verstaan ​​wat allergieë veroorsaak, en hoekom die voorkoms van voedselallergieë oor die afgelope paar dekades toegeneem het. Sindher se hoofdoel is om nuwe maniere te vind om allergieë te behandel (en hopelik genees). Die mees gevestigde tegniek (vir voedselallergieë, ten minste) is orale immunoterapie, waar allergiese individue geleidelik meer van hul allergeen eet totdat hulle klein hoeveelhede kan hê sonder om 'n reaksie te ervaar. Dit word gewoonlik uiters geleidelik gedoen, oor die loop van maande of jare, en altyd onder die toesig van 'n gesertifiseerde allergis.

iStock

Sindher sê wetenskaplikes toets steeds ander soorte immunoterapie-behandelings en inentings in kliniese proewe: "Baie navorsing gaan om die oorsake te probeer identifiseer sodat ons suksesvol kan wees in die voorkoming sowel as die behandeling van voedselallergieë."

Totdat dit egter gebeur, sê dokters die beste manier van aksie is om versigtig te wees rondom allergene. Medikasie is nuttig en nodig, maar voorkoming is die naam van die spel wanneer dit by allergieë kom.


Kan allergieë die dood veroorsaak?

’n Allergie word gekenmerk deur ’n oorreaksie van die menslike immuunstelsel op ’n vreemde proteïenstof (“allergeen”) wat geëet, in die longe ingeasem, ingespuit of aangeraak word. Hierdie immuun-oorreaksie, soos ons almal weet, kan lei tot simptome soos hoes, nies, jeukerige oë, loopneus en krapperige keel. In ernstige gevalle wat ons dalk nie ken nie, kan dit ook lei tot uitslag, korwe, laer bloeddruk, moeilike asemhaling, asma-aanvalle en selfs die dood.

Wat ons ook moet weet, is dat die menslike liggaam gevul is met spesiale selle, stelsels en organe wat gereed staan ​​om indringers te beveg. Die mikrobioom is een van die belangrikstes en is op verskeie strategiese plekke in en op die liggaam geleë en monitor wat die liggaam binnegaan, insluitend die vel, mond en neusgange. Die immuunstelsel sluit die mikrobioom en ander selle en sisteme in.

Anafilakse is een ernstige allergiese reaksie wat vinnig begin en die dood kan veroorsaak. Dit veroorsaak gewoonlik 'n aantal simptome, insluitend 'n jeukerige uitslag, swelling van die keel en lae bloeddruk. Algemene oorsake sluit in insekbyte en -steek, kos en medikasie.

So wat is 'n allergie?

'N allergie is 'n oorreaksie van die immuunstelsel op 'n stof wat’s skadeloos vir die meeste mense. Maar in iemand met 'n allergie, die liggaam’ se immuunstelsel behandel die stof (genoem 'n allergeen) as 'n indringer en oorreageer, wat simptome veroorsaak wat kan wissel van irriterende tot ernstig of lewensgevaarlik.

In 'n poging om die liggaam te beskerm, produseer die immuunstelsel van die allergiese persoon teenliggaampies wat immunoglobulien E (IgE) genoem word. Daardie teenliggaampies veroorsaak dan dat mastselle en basofiele (allergieselle in die liggaam) chemikalieë (insluitend histamien) in die bloedstroom vrystel om teen die allergeen “indringer.” te verdedig.

Dit is die vrystelling van hierdie chemikalieë wat allergiese reaksies veroorsaak, wat 'n persoon se oë, neus, keel, longe, vel of spysverteringskanaal aantas, aangesien die liggaam se immuunstelsel probeer om homself van die indringende allergeen te ontslae te raak. Toekomstige blootstelling aan dieselfde allergeen sal hierdie allergiese reaksie weer veroorsaak. Dit beteken dat elke keer as die persoon daardie spesifieke kos eet of aan daardie spesifieke allergeen blootgestel word, hy of sy 'n allergiese reaksie sal hê.

Allergieë kan seisoenaal wees (kom slegs op sekere tye van die jaar voor, soos wanneer stuifmeeltellings hoog is) of kan voorkom wanneer iemand met 'n allergeen in aanraking kom.

Wat veroorsaak allergieë tydens swangerskap?

Daar is 'n uitstekende verduideliking op die Mom-Loves-Best-blogplasing, hulle sal jou ook die scoop gee oor alles wat jy al ooit gewonder het oor swangerskap, bevalling en moederskap.

'n Effektiewe manier om te ontdek watter allergieë jy in jou liggaam kan hê sonder om na jou dokter te gaan.

Die Kwaliteit Gesondheid Ontleder is 'n wonderlike hulpmiddel om in jou huis te hê om vir jou gesin te gebruik om uit te vind watter allergieë jou en jou ouer kinders affekteer. Hierdie ontleder is 'n ultraklankskanderingstoestel wat die verskillende selfrekwensies in jou liggaam optel en met gesofistikeerde sagteware 'n gedetailleerde verslag lewer. Daar is meer as 30 verslae en elkeen het subverslae insluitend verduidelikings. Die prent hieronder is 'n skermskoot van 'n tipiese verslag oor allergieë.

Allergieë (outo-immuun)

Intermitterende vas ondersteun natuurlik die liggaam’ se immuunstelsel, kommunikeer immuun inligting meer doeltreffend tussen die mitochondria in die selle in die liggaam, en uiteindelik die verbetering van die liggaam’s vermoë om aanvalle op sy gesondheid te weerstaan. Vas genees nie siektes of maak kieme dood nie. Dit is ons immuunstelsel wat ons teen kieme, kanker en ander siektes beskerm. Intermitterende vas kan die immuunstelsel versterk, versterk of onderdruk (in die geval van outo-immuun siekte), maar gaan veel verder as hierdie effekte. Volgens bekende mediese spesialiste soos dr Jason Fung is vas die belangrikste deurbraak in die gesondheidsorgbedryf in hierdie eeu.

Vas handel oor ons induseerders en onderdrukkers wat die immuunstelsel’ se reaksie op siektes en allergieë reguleer. Die induseerders word deur die “brein” gebruik om meer “combat” selle te aktiveer in die stryd teen kieme, siektes en stowwe wat allergieë veroorsaak. Die onderdrukkers is baie belangrik om jou gesondheid te handhaaf. Wanneer kieme die liggaam binnedring of 'n gemuteerde sel kankeragtig word, lei die geaktiveerde mTOR, wat as die “brein” van die immuunstelsel dien, hierdie immuunselle versigtig na die teiken en dan om die swak selle skoon te maak wat nie hul werk doen nie. .

Soms oorreageer immuunselle op 'n indringer en vernietig die slagveld, wat jou liggaamsweefsel is. Soms sal die immuunstelsel eintlik sy eie liggaam as die vyand teiken en dit aanval. Dit word 'n outo-immuunversteuring genoem. Vas is belangrik om die insulienhormone in die bloed te reguleer sodat jy nie outo-immuunafwykings sal ontwikkel of oorgewig sal word nie. Daar is honderde verskillende outo-immuun siektes insluitend diabetes en sekere allergieë. Baie mense weet nie eers dat dit waaraan hulle ly 'n outo-immuun siekte is nie. Selfs allergieë is 'n tipe disfunksionele immuunstelsel wat die verkeerde teiken aanval.

Teenliggaam

'n Teenliggaam is 'n proteïen (ook 'n immunoglobulien genoem) wat deur limfosiete ('n tipe witbloedsel) vervaardig word om 'n antigeen of vreemde proteïen te neutraliseer. Bacteria, viruses and other microorganisms commonly contain many antigens, as do pollens, dust mites, moulds, foods, and other substances. Although many types of antibodies are the protective, inappropriate or excessive formation of antibodies may lead to illness. When the body forms a type of antibody called IgE (immunoglobulin E), allergic rhinitis, asthma or eczema may result when the patient is again exposed to the substance which caused IgE antibody formation (allergen).

Antigeen

An antigen is a substance that can trigger an immune response, resulting in the production of an antibody as part of the body’s defence against infection and disease. Many antigens are foreign proteins (those not found naturally in the body). An allergen is a special type of antigen which causes an IgE antibody response.

Allergies are hypersensitive immune responses to substances that either enter or come in contact with the body, such as pet dander, pollen or bee venom. A substance that causes an allergic reaction is called an “allergen”. Allergens can be found in food, drinks or the environment.

Most allergens are harmless, i.e. the majority of people are not affected by them.

If you are allergic to a substance, such as pollen, your immune system reacts to it as if it were a pathogen (a foreign harmful substance), and tries to destroy it.

The steepest increase in allergies has been observed in children, particularly food allergies.

A team of researchers from Northwestern University Feinberg School of Medicine reported in Pediatrie that about 8% of American children have some kind of food allergy. 38.7% of those with food allergies have a history of anaphylaxis (severe allergic reactions), and 30.4% are allergic to more than one food.

Researchers from St. Luke’s Roosevelt Hospital Center, New York, found that foreign-born children who live in the USA have a lower risk of allergies. This risk grows the longer they remain in America. This gives us food for thought as they have developed a different microbiome.

The following may be signs of an allergic reaction to medication:

  • Wheezing
  • Swollen tongue
  • Swollen lips
  • Swelling of the face
  • Veluitslag
  • Itchiness
  • Anaphylaxis.

Signs and symptoms of anaphylaxis

Anaphylaxis is a serious allergic reaction with a rapid onset. Anaphylaxis can be life-threatening and must be treated as a medical emergency.

This type of allergic reaction presents several different symptoms which can appear minutes or hours after exposure to the allergen. If the exposure is intravenous, the onset is usually between 5 to 30 minutes. A food allergen will take longer.

Anaphylaxis is a medical emergency

Researchers from the University of Manitoba, Canada, reported in The Journal of Allergy & Clinical Immunology that the most commonly affected areas in anaphylaxis are the skin (80-90%), respiratory (70%), gastrointestinal (30-45%), cardiovascular 10-45%) and the central nervous system (10-15%). In most cases, two areas are affected simultaneously.

The immune system of a person with an allergy reacts to the allergen as though it were a harmful pathogen – such as an undesirable bacteria, virus, fungus or toxin. However, the allergen is not harmful. The immune system has simply become oversensitive to that substance which means the immune system has to be educated.

It always comes back to the immune system in one way or another . In this day and age with the evidence that immunology science has given us, we need to firstly ensure our immune system is strong, balanced and kept intelligent with healthy eating and intermittent fasting.

The human body is filled with all types of special systems, cells and organs that stand ready to fight invaders. Together they are called the immune system – is your system ready and able to fight all diseases? Jou Quality Health Analyser will tell you in great detail.

Aflaai my free e-book “Grow yourself back to health” and join my bi-monthly blogs on the latest scientific evolution in health.

Total Health is our BirthRight,
Michael Plumstead


Cross sensitivity

There is partial cross-sensitivity between different types of penicillins. An individual who has exhibited immediate type of hypersensitivity with one penicillin should not be given any other type of penicillin. Until recently it has been accepted that there was up to a 10 % cross sensitivity between penicillin-derivatives, cephalosporins, and carbapenems, due to the sharing of the ß-lactam ring. Recent papers have shown that the major determinant in the immunological reaction is the similarity between the side chain of first generation cephalosporins and penicillins, rather than the ß-lactam structure that they share. This means that the risk of an allergic reaction to cephalosporins in those with an established IgE-mediated allergy to penicillin may be low or non-existent, as long as the side chains are not similar. The cephalosporin medications that are likely to cross-react after penicillin allergies have been established and include:

Among those that lack the ß-lactam side chain, and would therefore be safer, are:

We should be aware that cephalosporin cross-reactivity in a penicillin-allergic patient is not necessarily a class effect. Dispensing of a prescription in a penicillin-allergic patient should be evaluated based on the type of allergic manifestations and the drug prescribed[6].

The other side of the discussion is whether those allergic to cephalosporins can safely receive penicillin. Anaphylactic reactions to cephalosporins are much less common than anaphylaxis associated with penicillin. Persons who make IgE in response to cephalosporins seem to produce it only in response to a particular cephalosporin, whereas persons who make clinically significant IgE in response to penicillin tend to react to core penicillin break-down products. Thus, in a patient with a history of a serious, potentially IgE-mediated reaction to a cephalosporin, it is critical to avoid re-exposure to the same cephalosporin, to a cephalosporin that shares the same side chain, and even to other ß-lactams that share the same side chain (such as ceftazidime and aztreonam). Another thing to remember when thinking about medication for patients with a penicillin allergy is that there is a three-fold increased coincidental risk of adverse reactions to even an unrelated drug. Penicillin-allergic patients are more likely to react to any class of drug, so extra care is required[7,8].


Anaphylaxis: Synopsis

Richard F. Lockey, MD
Professor of Medicine, Pediatrics and Public Health
Director of the Division of Allergy and Immunology
Joy McCann Culverhouse Chair of Allergy and Immunology
University of South Florida College of Medicine and the James A. Haley Veterans' Hospital
Tampa, Florida, USA

This disease summary is provided for informational purposes for physicians only.

Definition of Anaphylaxis

Anaphylaxis is an acute, potentially life-threatening hypersensitivity reaction, involving the release of mediators from mast cells, basophils and recruited inflammatory cells. Anafilakse word gedefinieer deur 'n aantal tekens en simptome, alleen of in kombinasie, wat binne minute, of tot 'n paar uur, na blootstelling aan 'n uitlokkende middel voorkom. Dit kan lig, matig tot ernstig of ernstig wees. Die meeste gevalle is lig, maar enige anafilakse het die potensiaal om lewensgevaarlik te word.

Anaphylaxis develops rapidly, usually reaching peak severity within 5 to 30 minutes, and may, rarely, last for several days.

Klassifikasie

Die term anaphylaxis is often reserved to describe immunological, especially IgE-mediated reactions. A second term, non-allergic anaphylaxis, describes clinically identical reactions that are not immunologically mediated. The clinical diagnosis and management are, however, identical.

Symptoms and Signs of Anaphylaxis

The initial manifestation of anaphylaxis may be loss of consciousness. Patients often describe "a sense of doom." In this instance, the symptoms and signs of anaphylaxis are isolated to one organ system, but since anaphylaxis is a systemic event, in the vast majority of subjects two or more systems are involved.

Gastro-intestinal: Abdominal pain, hyperperistalsis with faecal urgency or incontinence, nausea, vomiting, diarrhea.

Oral: Pruritus of lips, tongue and palate, edema of lips and tongue.

Respiratory: Upper airway obstruction from angioedema of the tongue, oropharynx or larynx bronchospasm, chest tightness, cough, wheezing rhinitis, sneezing, congestion, rhinorrhea.

Cutaneous: Diffuse erythema, flushing, urticaria, pruritus, angioedema.

Kardiovaskulêre: Faintness, hypotension, arrhythmias, hypovolemic shock, syncope, chest pain.

Ocular: Periorbital edema, erythema, conjunctival erythema, tearing.

Genito-urinary: Uterine cramps, urinary urgency or incontinence.

Severe initial symptoms develop rapidly, reaching peak severity within 3-30 minutes. There may occasionally be a quiescent period of 1&ndash8 hours before the development of a second reaction (a biphasic response). Protracted anaphylaxis may occur, with symptoms persisting for days. Death may occur within minutes but rarely has been reported to occur days to weeks after the initial anaphylactic event.

Causes of Anaphylaxis

1. IgE-Mediated Reactions

Kos

In theory, any food glycoprotein is capable of causing an anaphylactic reaction. Foods most frequently implicated in anaphylaxis are:

  • Peanut (a legume)
  • Tree nuts (walnut, hazel nut/filbert, cashew, pistachio nut, Brazil nut, pine nut, almond)
  • Vis
  • Shellfish (shrimp, crab, lobster, oyster, scallops)
  • Milk (cow, goat)
  • Chicken eggs
  • Seeds (cotton seed, sesame, mustard)
  • Fruits, vegetables

Food sensitivity can be so severe that a systemic allergic reaction can occur to particle inhalation, such as the odors of cooked fish or the opening of a package of peanuts.

A severe allergy to pollen, for example, ragweed, grass or tree pollen, can indicate that an individual may be susceptible to anaphylaxis or to the oral allergy syndrome (pollen/food syndrome) (manifested primarily by severe oropharyngeal itching, with or without facial angioedema) caused by eating certain plant-derived foods. This is due to homologous allergens found between pollens and foods. The main allergen of all grasses is profilin, which is a pan-allergen, found in many plants, pollens and fruits, and grass-sensitive individuals can sometimes react to many plant-derived foods.

Typical aero-allergen food cross-reactivities are:

  • Birch pollen: apple, raw potato, carrot, celery and hazelnut
  • Mugwort pollen: celery, apple, peanut and kiwifruit
  • Ragweed pollen: melons (watermelon, cantaloupe, honeydew) and banana
  • Latex: banana, avocado, kiwifruit, chestnut and papaya

Food-associated, exercise-induced anaphylaxis may occur when individuals exercise within 2-4 hours after ingesting a specific food. The individual is, however, able to exercise without symptoms, as long as the incriminated food is not consumed before exercise. The patient is likewise able to ingest the incriminated food with impunity as long as no exercise occurs for several hours after eating the food.

Antibiotics and Other Drugs

PENICILLIN, CEPHALOSPORIN, AND SULPHONAMIDE ANTIBIOTICS

Penicillin is the most common cause of anaphylaxis, for whatever reason, not just drug-induced cases. Penicillin and other antibiotics are haptens, molecules that are too small to elicit immune responses but which may bind to serum proteins and produce IgE antibodies. Serious reactions to penicillin occur about twice as frequently following intramuscular or intravenous administration versus oral administration, but oral penicillin administration may also induce anaphylaxis. Neither atopy, nor a genetic history of allergic rhinitis, asthma or eczema, is a risk factor for the development of penicillin allergy.

Muscle relaxants, for example, suxamethonium, alcuronium, vecuronium, pancuronium and atracurium, which are widely used in general anesthesia, account for 70-80% of all allergic reactions occurring during general anesthesia. Reactions are caused by an immediate IgE-mediated hypersensitivity reaction.

Insekte

Hymenoptera venoms (bee, wasp, yellow-jacket, hornet, fire ant) contain enzymes such as phospholipases and hyaluronidases and other proteins which can elicit an IgE antibody response.

Lateks

Latex is a milky sap produced by the rubber tree Hevea brasiliensis. Latex-related allergic reactions can complicate medical procedures, for example, internal examinations, surgery, and catheterization. Medical and dental staff may develop occupational allergy through use of latex gloves.

Diverse

Examples of miscellaneous agents which cause anaphylaxis are insulin, seminal proteins, and horse-derived antitoxins, the latter of which are used to neutralize venom in snake bites. Individuals who have IgA deficiency may become sensitized to the IgA provided in blood products. Those selective IgA deficient subjects (1:500 of the general population) can develop anaphylaxis when given blood products, because of their anti-IgA antibodies (probably IgE-anti-IgA).

Elective Medical Procedures

2. Cytoxic and Immune Complex &ndash Complement-Mediated Reactions

Whole Blood, Serum, Plasma, Fractionated Serum Products, Immunoglobulins, Dextran

Anaphylactic responses have been observed after the administration of whole blood or its products, including serum, plasma, fractionated serum products and immunoglobulins. One of the mechanisms responsible for these reactions is the formation of antigen-antibody reactions on the red blood cell surface or from immune complexes resulting in the activation of complement. The active by-products generated by complement activation (anaphylatoxins C3a, C4a and C5a) cause mast cell (and basophil) degranulation, mediator release and generation, and anaphylaxis. In addition, complement products may directly induce vascular permeability and contract smooth muscle.

Cytotoxic reactions can also cause anaphylaxis, via complement activation. Antibodies (IgG and IgM) against red blood cells, as occurs in a mismatched blood transfusion reaction, activate complement. This reaction causes agglutination and lysis of red blood cells and perturbation of mast cells resulting in anaphylaxis.

3. Non-immunologic Mast Cell Activators

Radiocontrast Media, Low-molecular Weight Chemicals

Mast cells may degranulate when exposed to low-molecular-weight chemicals. Hyperosmolar iodinated contrast media may cause mast cell degranulation by activation of the complement and coagulation systems. These reactions can also occur, but much less commonly, with the newer contrast media agents.

Narcotics

Narcotics are mast cell activators capable of causing elevated plasma histamine levels and non-allergic anaphylaxis. They are most commonly observed by anesthesiologists.

4. Modulators of Arachidonic Acid Metabolism

Aspirin, Ibuprofen, Indomethacin and other Non-steroidal Anti-inflammatory Agents (NSAIDs)

IgE antibodies against aspirin and other NSAIDs have not been identified. Affected individuals tolerate choline or sodium salicylates, substances closely structurally related to aspirin but different in that they lack the acetyl group.

5. Sulfiting Agents

Sodium and Potassium Sulfites, Bisulfites, Metabisulfites, and Gaseous Sulfur Dioxides

These preservatives are added to foods and drinks to prevent discoloration and are also used as preservatives in some medications. Sulfites are converted in the acid environment of the stomach to SO2 en H2SO3, which are then inhaled. They can produce asthma and non-allergic hypersensitivity reactions in susceptible individuals.

6. Idiopathic Causes

Oefen

Exercise alone can cause anaphylaxis as can food-induced anaphylaxis, Exercise-induced anaphylaxis can occur during the pollinating season of plants to which the individual is allergic.

Catamenial Anaphylaxis

Catamenial anaphylaxis is a syndrome of hypersensitivity induced by endogenous progesterone secretion. Patients may exhibit a cyclic pattern of attacks during the premenstrual part of the cycle.

Idiopathic Anaphylaxis

Flushing, tachycardia, angioedema, upper airway obstruction, urticaria and other signs and symptoms of anaphylaxis can occur without a recognizable cause. Diagnosis is based primarily on the history and an exhaustive search for causative factors. Serum tryptase and urinary histamine levels may be useful, in particular, to rule out mastocytosis.

Emergency Treatment of Anaphylaxis

A = Airway

Ensure and establish a patent airway, if necessary, by repositioning the head and neck, endotracheal intubation or emergency cricothyroidotomy. Place the patient in a supine position and elevate the lower extremities. Patients in severe respiratory distress may be more comfortable in the sitting position.

B = Breathing

Assess adequacy of ventilation and provide the patient with sufficient oxygen to maintain adequate mentation and an oxygen saturation of at least 91% as determined by pulse oximetry. Treat bronchospasm as necessary. Equipment for endotracheal intubation should be available for immediate use in event of respiratory failure and is indicated for poor mentation, respiratory failure, or stridor not responding immediately to supplemental oxygen and epinephrine.

C = Circulation

Minimize or eliminate continued exposure to causative agent by discontinuing the infusion, as with radio-contrast media, or by placing a venous tourniquet proximal to the site of the injection or insect sting. Assess adequacy of perfusion by taking the pulse rate, blood pressure, mentation and capillary refill time. Establish I.V. access with large bore (16- to 18-gauge) catheter and administer an isotonic solution such as normal saline. A second I.V. may be established as necessary. If a vasopressor, such as dopamine becomes necessary, the patient requires immediate transfer to an intensive care setting.

The same ABC mnemonic can be used for the pharmacologic management of anaphylaxis:

A = Adrenalin = epinephrine

Epinephrine is the drug of choice for anaphylaxis. It stimulates both the beta-and alpha-adrenergic receptors and inhibits further mediator release from mast cells and basophils. Animal and human data indicate that platelet activating factor (PAF) mediates life-threatening manifestations of anaphylaxis. The early use of epinephrine in vitro inhibits the release of PAF in a time-dependent manner, giving support to the use of this medication with the first signs and symptoms of anaphylaxis. The usual dosage of epinephrine for adults is 0.3-0.5 mg of a 1:1000 w/v solution given intramuscularly, preferably in the anterolateral thigh, every 10-20 minutes or as necessary. The dose for children is 0.01 mg/kg to a maximum of 0.3 mg intramuscularly, preferably in the anterolateral thigh, every 5-30 minutes as necessary. Lower doses, e.g., 0.1 mg to 0.2 mg administered intramuscularly, preferably in the anterolateral thigh, as necessary, are usually adequate to treat mild anaphylaxis, often associated with skin testing or allergen immunotherapy. Epinephrine should be given early in the course of the reaction and the dose titrated to the clinical response. For severe hypotension, 1 cc of a 1:10,000 w/v dilution of epinephrine given slowly intravenously is indicated. The patient's response determines the rate of infusion.

B = Benadryl (diphenhydramine)

Antihistamines are not useful for the initial management of anaphylaxis but may be helpful once the patient stabilizes. Diphenhydramine may be administered intravenously, intramuscularly or orally. Cimetidine offers the theoretical benefit of reducing both histamine-induced cardiac arrhythmias, which are mediated via H2 receptors, and anaphylaxis-associated vasodilation, mediated by H1 and H2 receptors. Cimetidine, up to 300 mg every 6 to 8 hours, may be administered orally or slowly I.V. Doses must be adjusted for children.

C = Corticosteroids

Corticosteroids do not benefit acute anaphylaxis but may prevent relapse or protracted anaphylaxis. Hydrocortisone (100 to 200 mg) or its equivalent can be administered every 6 to 8 hours for the first 24 hours. Doses must be adjusted for children.

Prevention of Anaphylaxis

Agents causing anaphylaxis should be identified when possible and avoided. Patients should be instructed how to minimize exposure.

Beta-adrenergic antagonists, including those used to treat glaucoma, may exacerbate anaphylaxis and should be avoided, where possible. Angiotensin-converting enzyme (ACE) inhibitors may also increase susceptibility to anaphylaxis, particularly with insect venom-induced anaphylaxis.

Epinephrine is the drug of choice to treat anaphylaxis. Individuals at high risk for anaphylaxis should be issued epinephrine syringes for self-administration and instructed in their use. Intramuscular injection into the anterolateral thigh is recommended since it results in prompt elevation of plasma concentrations and has prompt physiological effects. Subcutaneous injection results in delayed epinephrine absorption. Patients must be alerted to the clinical signs of impending anaphylaxis and the need to carry epinephrine syringes at all times and to use it at the earliest onset of symptoms. Unused syringes should be replaced when they reach their use-by/expiration date, as epinephrine content and bioavailability of the drug decreases in proportion to the number of months past the expiration date.

Pre-treatment with glucocorticosteroids and H1 and H2 antihistamines is recommended to prevent or reduce the severity of a reaction where it is medically necessary to administer an agent known to cause anaphylaxis, for example, radio-contrast media.

Other important patient instructions include:

a) Personalized written anaphylaxis emergency action plan
b) Medical Identification (e.g., bracelet, wallet card)
c) Medical record electronic flag or chart sticker, and emphasis on the importance of follow-up investigations by an allergy/immunology specialist

Differential Diagnosis

The differential diagnosis for anaphylaxis includes:

  • respiratory difficulty or circulatory collapse, including vasovagal reactions
  • globus hystericus
  • status asthmaticus
  • foreign body aspiration
  • pulmonary embolism
  • epiglottitis
  • myocardial infarction
  • carcinoid syndrome
  • hereditary angioedema
  • pheochromocytoma
  • hipoglukemie
  • aanvalle
  • overdose of medication
  • cold urticaria
  • cholinergic urticaria
  • sulfite or monosodium glutamate ingestion

Upper airway obstruction, bronchospasm, abdominal cramps, pruritus, urticaria and angioedema are absent in vasovagal reactions. Pallor, syncope, diaphoresis and nausea usually indicate a vaso-vagal reaction but may occur in either condition.

If a reaction occurs during a medical procedure, it is important to consider a possible reaction to latex or medication used for or during anesthesia.

Epidemiologie

Food-induced anaphylaxis

The prevalence of food-induced anaphylaxis varies with the dietary habits of a region. A United States survey reported an annual occurrence of 10.8 cases per 100,000 person years. By extrapolating this data to the entire population of the USA, this suggests approximately 29,000 food-anaphylactic episodes each year, resulting in approximately 2,000 hospitalizations and 150 deaths. Similar findings have been reported in the United Kingdom and France. Food allergy is reported to cause over one-half of all severe anaphylactic episodes in Italian children treated in emergency departments and for one-third to one-half of anaphylaxis cases treated in emergency departments in North America, Europe and Australia. It is thought to be less common in non-Westernized countries. A study in Denmark reported a prevalence of 3.2 cases of food anaphylaxis per 100,000 inhabitants per year with a fatality rate of approximately 5%.

Risk factors for food anaphylaxis include asthma and previous allergic reactions to the causative food.

Food-associated, exercise-induced anaphylaxis

This is more common in females, and over 60% of cases occur in individuals less than 30 years of age. Patients sometimes have a history of reacting to the food when younger and usually have positive skin tests to the food that provokes their anaphylaxis.

Anaphylaxis caused by radio-contrast media

Mild adverse reactions are experienced by approximately 5% of subjects receiving radio-contrast media. U.S. figures suggest that severe systemic reactions occur in 1:1000 exposures with death in 1:10,000-40,000 exposures.

Penicillin-induced anaphylaxis

One percent to 5% of courses of penicillin therapy are complicated by systemic hypersensitivity reactions. Point two percent is associated with anaphylactic shock, and mortality occurs in 0.02% of the cases. If a patient has a strongly positive skin test or circulating IgE antibody to penicillin, there is a 50-60% risk of an anaphylactic reaction upon subsequent challenge. In patients with a case history suggestive of penicillin allergy and negative skin tests, the risk of anaphylaxis is very low. Atopy and mold sensitivity are not risk factors for the development of penicillin allergy.

Muscle relaxants

Anaphylaxis to muscle relaxants occurs in approximately 1 in 4,500 of general anesthesia, with fatalities occurring in 6% of these cases. Risk factors are female sex (80% of cases). Atopy is not a risk factor previous drug allergy may be a risk factor. In patients with a history of anaphylaxis, skin tests to different muscle relaxants may be helpful. If the test result is positive, the muscle relaxant should not be used. A negative result provides evidence that the muscle relaxant can probably be administered safely.

Insect venom anaphylaxis

Studies from Australia, France, Switzerland and the USA suggest incidences of systemic reactions to Hymenoptera stings ranging from 0.4% to 4% of the population. In the USA, at least 40 allergic deaths occur each year as a result of Hymenoptera steek.

Bestuur

Allergy / immunology specialists play a uniquely important role to confirm the etiology of anaphylaxis, prepare the patient for self administration of epinephrine, educate the patient and/or family about allergen avoidance, and rule out any underlying condition, such as mastocytosis, which can predispose a patient to develop anaphylaxis. Referral to an allergist / immunologist is indicated for patients with this disease.


Anaphylaxis and mast cell reactions

Author’s note: I am not a medical doctor. Anaphylaxis and use of epinephrine must be discussed with the managing provider to determine the best treatment plan for any individual patient.

Determination of mast cell reaction vs anaphylaxis

Anaphylaxis has a very complicated relationship with mast cell disease. Mast cell symptoms and reactions are inherent parts of mast cell disease. All mast cell patients can reasonably expect to have some mast cell symptoms as part of their baseline.

Anaphylaxis is not an inherent part of mast cell disease. Anaphylaxis is a complication of mast cell disease. Mast cell patients are at increased risk for anaphylaxis, but not all mast cell patients experience anaphylaxis. In some studies, as many as 50% of mast cell patients had never experienced anaphylaxis.

The fact that anaphylaxis and mast cell reactions can have the same symptoms is probably the reason why it is difficult to separate the two. So for a minute, let’s stop talking about mast cell disease and consider a similar scenario that is better described.

  • Coronary artery disease (CAD) is the leading cause of death worldwide. It affects millions of people around the world. Everyone knows someone with coronary artery disease. Probably multiple someones.
  • Patients with CAD have narrow arteries that interfere with blood flow to the heart. When they are diagnosed with CAD, their provider will tell them about symptoms they may experience daily as a normal part of their disease. Their provider will also tell them about symptoms that they may experience that indicate the heart is not getting enough oxygen, like radiating chest pain, shortness of breath and nausea. In these scenarios, the patient needs to take a med like nitroglycerin to try and stop the episode. If that doesn’t work, the patient is at risk for a heart attack.
  • Radiating chest pain, shortness of breath and nausea are symptoms of CAD. Heart attack is not a symptom of CAD. It is a complication of CAD. It can also present with the same symptoms of radiating chest pain, shortness of breath and nausea.

Flushing, nausea, diarrhea and hives are symptoms of mast cell disease. (I’m just using these as examples, there are many others). Anaphylaxis is not a symptom of mast cell disease. It is a complication of mast cell disease. It can also present with the same symptoms of flushing, nausea, diarrhea and hives.

These are the potential scenarios when a mast cell patient starts experiencing more severe symptoms than usual.

  1. The patient experiences flushing, nausea, diarrhea and hives. They don’t take rescue meds and the symptoms resolve. This is a mast cell reaction. This is not anaphylaxis .
  2. The patient experiences flushing, nausea, diarrhea and hives. They take rescue meds (not including epi here) and the symptoms resolve. This is a mast cell reaction. This is not anaphylaxis .
  3. The patient experiences flushing, nausea, diarrhea and hives. They may or may not take rescue meds (not including epi here). Either way, the symptoms do not resolve. The amount of mast cell degranulation triggers a large scale reaction that initiates anaphylaxis. This is anaphylaxis and requires epinephrine. There are two possibilities here: it was anaphylaxis from the beginning, or it started as a mast cell reaction and became anaphylaxis. Either way, it requires epinephrine and other rescue meds.

It seems to me that when anaphylaxis occurs in mast cell patients as a sudden onset event that the symptoms seen are usually distinct from regular mast cell reaction symptoms. (This last sentence is based upon what I have experienced and what is reported to me by patients. There is no data on this.)

General notes on use of epinephrine

How do you know it is anaphylaxis? That’s the hard part. Mast cell experts feel differently about this. Most say to only use epi if you have trouble breathing or low blood pressure because then you know it is life threatening and thus anaphylaxis and not a mast cell reaction.

If you are having trouble breathing or low blood pressure (for adults, under 90 systolic), that is generally cited as the appropriate point to use epi. However, it is a conversation and decision that must be made with you and a doctor that knows you and your disease.

If you have had an episode before where you had severe symptoms and recovered without epinephrine, it is phenomenally unlikely that it was anaphylaxis.

If you think you may need epinephrine and are unsure, it is generally recommended to use your epipen. The reason for this is that epinephrine is pretty safe, despite how the movies depict it. The risk of using an epipen when you don’t need it is side effects of epinephrine use: rapid heartbeat, elevated blood pressure, anxiety, and generally not feeling great for a day or so. The risk of not using an epipen when you need it is death. People die from anaphylaxis with their epipens on them unused.

Meeting diagnostic criteria for anaphylaxis

As I reviewed in the previous post, there are many sets of diagnostic criteria for anaphylaxis. The one that is the most widely used in the WAO criteria published in 2006. This set of criteria has been validated, meaning it was effective for correctly identifying patients experiencing anaphylaxis while excluding those who weren’t. Even still, they note that about 5% of patients with anaphylaxis will not be covered by these criteria and to use discretion with this population.

The 2006 WAO criteria (shown below) are often used by emergency departments to determine whether or not epinephrine is needed. If the patient meets the criteria, epi is warranted. This is one of the reasons why anaphylaxis is often considered synonymous with requirement of epinephrine.

2006 WAO Anaphylaxis Criteria

Determining whether or not you have anaphylaxis when your blood pressure is not very low and you can breathe fine is not straightforward for mast cell patients. There are several charts that are often posted in mast cell groups that show four or five stages of anaphylaxis. These charts are designed for people who do not have baseline allergic symptoms. Mast cell patients have baseline allergic symptoms.

If you have mast cell disease and have flushing, nausea and hives regularly, that is not grade II anaphylaxis. That is mast cell disease. Symptoms that are part of your normal baseline or reaction profile do not contribute to the overall assessment of anaphylaxis. So let’s assume I have flushing, nausea and hives every day. But then one day I also have diarrhea and tachycardia, which isn’t normal for me. That is grade III anaphylaxis per the Ring and Messmer scale (shown below). Whether or not you use epi at that point, assuming your blood pressure is not low and you can breathe okay, depends upon whether or not your doctor endorses the use of that scale.

Ring and Messmer Anaphylaxis Grading Scale

A naphylaxis vs anaphylactic shock

I often see people use anaphylaxis and anaphylactic shock interchangeably. They’re not the same thing.

Anaphylaxis is a severe, multisystem allergic reaction.

Shock is more properly called circulatory shock. It is a state arising from poor circulation such that tissues are not receiving sufficient blood supply. Weak pulse, tachycardia, low heart rate, and mental status changes including loss of consciousness are all symptoms of shock.

Anaphylactic shock is circulatory shock caused by low blood pressure due to the vasodilation from large scale degranulation. By definition, it is blood pressure 30% below the patient’s baseline or below standard values (90 systolic for adults). So if you aren’t experiencing circulatory shock, you aren’t having anaphylactic shock.

Sampson HA, et al. Second symposium on the definition and management of anaphylaxis: summary report – Second National Institute of Allergy and Infectious Disease/Food Allergy and Anaphylaxis Network symposium. J Allergy Clin Immunol 2006: 117(2), 391-397.

Brown, SGA. Clinical features and severity grading of anaphylaxis. Journal of Allergy and Clinical Immunology 2004: 114(2), 371-376.

Sampson HA, et al. Symposium on the definition and management of anaphylaxis: summary report. J Allergy Clin Immunol 2005 115(3), 584-591.

Ring J, et al. History and classification of Anaphylaxis. Chem Immunol Allergy 2010: 95, 1-11.


Kyk die video: Anafilaksa (Oktober 2022).