COVID-19:Advice,updatesandvaccineoptionsWeareopenforsafein-personcare.Learnmore:MayoClinicfactsaboutcoronavirusdisease2019(COVID-19)OurCOVID-19patientandvisitorguidelines,plustrustedhealthinformationLateston COVID-19vaccination bysite:ArizonapatientvaccinationupdatesArizona,FloridapatientvaccinationupdatesFlorida,RochesterpatientvaccinationupdatesRochesterandMayoClinicHealthSystempatientvaccinationupdatesMCHSSkiptositenavigationSkiptoContentThiscontentdoesnothaveanEnglishversion.ThiscontentdoesnothaveanArabicversion.SectionsforDrugallergySymptoms&causesDiagnosis&treatmentDoctors&departmentsPrintOverviewAdrugallergyistheabnormalreactionofyourimmunesystemtoamedication.Anymedication—over-the-counter,prescriptionorherbal—iscapableofinducingadrugallergy.However,adrugallergyismorelikelywithcertainmedications.Themostcommonsignsandsymptomsofdrugallergyarehives,rashorfever.Adrugallergymaycauseseriousreactions,includingalife-threateningconditionthataffectsmultiplebodysystems(anaphylaxis).Adrugallergyisnotthesameasadrugsideeffect,aknownpossiblereactionlistedonadruglabel.Adrugallergyisalsodifferentfromdrugtoxicitycausedbyanoverdoseofmedication.Products&ServicesBook:MayoClinicFamilyHealthBook,5thEditionNewsletter:MayoClinicHealthLetter—DigitalEditionShowmoreproductsfromMayoClinicSymptomsSignsandsymptomsofaseriousdrugallergyoftenoccurwithinanhouraftertakingadrug.Otherreactions,particularlyrashes,canoccurhours,daysorweekslater.Drugallergysignsandsymptomsmayinclude:SkinrashHivesItchingFeverSwellingShortnessofbreathWheezingRunnynoseItchy,wateryeyesAnaphylaxisAnaphylaxisisarare,life-threateningreactiontoadrugallergythatcausesthewidespreaddysfunctionofbodysystems.Signsandsymptomsofanaphylaxisinclude:Tighteningoftheairwaysandthroat,causingtroublebreathingNauseaorabdominalcrampsVomitingordiarrheaDizzinessorlightheadednessWeak,rapidpulseDropinbloodpressureSeizureLossofconsciousnessOtherconditionsresultingfromdrugallergyLesscommondrugallergyreactionsoccurdaysorweeksafterexposuretoadrugand