Evaluation of drug-related hypersensitivity reactions in children.

Patients with drug reactions are often referred to allergists for "allergy". Skin testing and clinical history seem to have a good negative predictive value, however, although drug challenge could be dangerous, it is the only way to confirm the diagnosis. We aimed to demonstrate that most children with a history of non-life-threatening drug reactions do not have a true drug allergy and examined the use of drug challenge in childhood. Patients with reactions were referred to our clinic by pediatricians. In 1 year, 354 reactions were studied in 239 children. Patients were classified according to their positive or negative history of drug allergy. Skin prick testing was done in all cases. Exclusion criteria for challenge included drug anaphylaxis, Stevens-Johnson syndrome, systemic reactions with severe concomitant illness, beta-inhibitor drug therapy or positive skin test to the implicated drug with a positive history. It was found that the beta-lactam antibiotics were involved in 50% of suspected reactions, aspirin in 10% and sulfonamides in 9%. Histories were considered positive only in 25%. Drug challenges confirmed only 4% of all reactions. It was concluded that drug challenge may be the gold standard for most childhood reactions that are considered to be allergic, non-life-threatening and drug-related. Only 4% of these suspected reactions were exclusively caused by drug allergy.