Self‐reported drug allergy in a general adult Portuguese population

Abstract

Aim To estimate the prevalence of self‐reported drug allergy in adults. Methods Cross‐sectional survey of a general adult population from Porto (all of whom were living with children involved in the International Study of Asthma and Allergies in Childhood–phase three), during the year 2002, using a self‐administered questionnaire. Results The prevalence of self‐reported drug allergy was 7.8% (181/2309): 4.5% to penicillins or other β‐lactams, 1.9% to aspirin or other non‐steroidal anti‐inflammatory drugs (NSAIDs) and 1.5% to other drugs. In the group ‘allergic to β‐lactams’, the most frequently implicated drug was penicillin G or V (76.2%) followed by the association of amoxicillin and clavulanic acids (14.3%). In the group ‘allergic to NSAIDs’, acetylsalicylic acid (18.2%) and ibuprofen (18.2%) were the most frequently identified drugs, followed by nimesulide and meloxicam. Identification of the exact name of the involved drug was possible in less than one‐third of the patients, more often within the NSAID group (59.5%). Women were significantly more likely to claim a drug allergy than men (10.2% vs. 5.3%). The most common manifestations were cutaneous (63.5%), followed by cardiovascular symptoms (35.9%). Most of the reactions were immediate, occurring on the first day of treatment (78.5%). Only half of the patients were submitted to drug allergy investigations. The majority (86.8%) completely avoided the suspected culprit drug thereafter. Conclusions The results showed that self‐reported allergy to drugs is highly prevalent and poorly explored. Women seem to be more susceptible. β‐lactams and NSAIDs are the most frequently concerned drugs.