Cross sectional questionnaire-based internet study: Self-perception and clinical course of drug allergy in Greece.

BACKGROUND: Data on self perception of drug allergy in the general population are lacking. Epidemiological studies focus either on specific populations or document adverse drug reactions in general. Our objective was to document self-reported drug allergy in Greece, through a simple, informative internet-based questionnaire. METHODS: A questionnaire on drug allergy was accessible online for a 3-month period. Participants voluntarily answered 28 questions referring to: suspected drug, clinical manifestations, concomitant factors, received treatment, reaction's re-occurrence. RESULTS: A total of 2528 questionnaires were included in study analysis. Beta-lactams and non-steroidal anti-inflammatory drugs were the most prevalent culprit agents (53% and 27.5% respectively) while half of the participants acknowledged skin manifestations as the most common symptoms. One out of three reported subsequent exposure to the drug presumed to be responsible for the reaction and 74.5% of those stated a new reaction upon re-exposure. Only 26.7% underwent allergological evaluation. Reactions manifested with respiratory or cardiovascular symptoms, parenteral administration of the culprit drug and personal history of allergy to agents of >1 different pharmacological categories were associated with increased risk of hospitalization. CONCLUSIONS: Allergic reactions to drugs are adverse events difficult to define and diagnose. A remarkable proportion of presumed as hypersensitivity reactions are not referred to allergists; therefore these patients may be either re-exposed to potentially noxious drugs, or needlessly avoid whole classes of drugs as b-lactams for more costly or less appropriate treatments. Internet-based questionnaires may contribute to awareness programs concerning drug allergy and help improve proper referral.