HypersensitivityFromWikipedia,thefreeencyclopediaJumptonavigationJumptosearchForotheruses,seeHypersensitivity(disambiguation).ThisarticlemayrequirecleanuptomeetWikipedia'squalitystandards.Thespecificproblemis:contentiouscategorisation,poorreferencesPleasehelpimprovethisarticleifyoucan.(September2019)(Learnhowandwhentoremovethistemplatemessage)MedicalconditionHypersensitivitySpecialtyImmunologyHypersensitivity(alsocalledhypersensitivityreactionorintolerance)referstoundesirablereactionsproducedbythenormalimmunesystem,includingallergiesandautoimmunity.Theyareusuallyreferredtoasanover-reactionoftheimmunesystemandthesereactionsmaybedamaginganduncomfortable.Thisisanimmunologictermandisnottobeconfusedwiththepsychiatrictermofbeinghypersensitivewhichimpliestoanindividualwhomaybeoverlysensitivetophysical(iesound,touch,light,etc.)and/oremotionalstimuli.Althoughthereisarelationbetweenthetwo-studieshaveshownthatthoseindividualsthathaveADHD(apsychiatricdisorder)aremorelikelytohavehypersensitivityreactionssuchasallergies,asthma,eczemathanthosewhodonothaveADHD.[1]TypesofhypersensitivityreactionsHypersensitivityreactionscanbeclassifiedintofourtypes.TypeI-IgEmediatedimmediatereactionTypeII-Antibody-mediatedcytotoxicreaction(IgGorIgMantibodies)TypeIII-Immunecomplex-mediatedreactionTypeIV-Cell-mediated,delayedhypersensitivityreaction[2]Thefirstthreetypesareconsideredimmediatehypersensitivityreactionsbecausetheyoccurwithin24hours.Thefourthtypeisconsideredadelayedhypersensitivityreactionbecauseitusuallyoccursmorethan12hoursafterexposuretotheallergen,withamaximalreactiontimebetween48and72hours.[3]Contents1GellandCoombsclassification2TypeIhypersensitivity2.1Etiology2.2Typesofantigensinvolved3TypeIIhypersensitivity4TypeIIIhypersensitivity5TypeIVhypersensitivity5.1Pathophysiology6Treatment/Management6.1Immediatehypersensitivityreactions6.2Delayedhypersensitivityreactions7References8ExternallinksGellandCoombsclassification[edit]TheGellandCoombsclassificationofhypersensitivityisthemostwidelyus