为什么头孢菌素类不需做皮试.ppt

为什么头孢菌素类不需做皮试?2008,6,2,北京1为什么青霉素需要/可以做皮试?Approximately300deathscanbeattributedtopenicillinallergyeachyearintheUnitedStates. AllergytoBetaLactamAntibioticsJuly26,2007Fatalpenicillin-%amongthegeneralpopulation,with500to1,000deathsperyear. ArchInternMed2001:161:15~212ClassificationSchemeforAdverseDrugReactionsDescribedbyGellandCoombs3TypesofAllergicReactionstoPenicillinsandCephalosporins4******西林致过敏的斑丘疹5氨苄西林致敏的荨麻疹6为什么青霉素需要/可以做皮试?1,青霉素过敏反应发生率较高,为1%-10%;%–%(%),即1/7,000-25,000,死亡率为1/50,000-60,000;2,过敏反应的抗原—主要决定簇-青霉噻唑决定簇与次要决定簇-青霉烯酸决定簇非常明确;3,皮试符合率可达70%;但是—Penicillinskintestingdoesnotprovideanyinformationaboutcertaintypesofreactions; ,皮试液的浓度与皮试方法均已定型。5,80%~90%青霉素过敏史者,再次皮试可为阴性,因IgE可逐渐消失;.NEnglJMed2006;354:601-;354:601-98为什么准确率仅能达到70%?Thebreakdownproductsofpenicillinincludethepenicilloylgroup,knownasthemajordeterminantbecauseitisthemajorpenicillinmetabolicproduct(approximately85%to90%ofthepenicillinbreakdownproducts). Theminorhaptenicdeterminantsorminordeterminantmixture,socalledbecausetheyareformedinsmallerquantities,posedoftheparentpenicillinmolecules,penicilloate,penicilloylamine,penilloate,%?Apenicillinskintestdoesnotpredictnon-IgE-mediatedreactionscausedbyotherimmunemechanisms,suchascytotoxicantibody-mediatedreactions,antibody-plex-mediatedreactions,anddelayed-typecell-mediatedreactions.NegativeskintestingindicatesthatthepreviousreactionwasnotIgE-