Diagnostic evaluation and risk factors for drug allergies in children: from clinical history to skin and challenge tests

Background Parent or self-reported drug allergy claims frequently overestimate the real incidence of hypersensitivity reactions. A detailed and algorithmic diagnostic evaluation of drug reactions may allow a proper diagnosis. Objective The aim of this study was to determine the confirmation rates and risk factors for confirmed allergic drug reactions in children. Setting Mersin University Hospital in Turkey. Method The study consisted of children between ages of 8 months and 18 years with the history of suspected drug allergy as reported by the clinician or the patients. Parents were interviewed by a clinician to complete questionnaires that included questions about demographic data and characteristics of index drug reaction. Immediate reactions (IRs) were assessed with immediate-reading skin prick (SPT) and intradermal tests (IDT). Nonimmediate reactions (NIRs) were assessed with SPT, both early and delayed reading of IDT and patch tests. In case of negative skin tests, drug provocation tests were performed. The possible risk factors for confirmed drug allergy in univariate analysis (p < 0.1) were entered into the multivariate logistic regression analysis to determine independent predictors. Main outcome measure (1) Confirmation rates of drug allergy (2) Risk factors related to confirmed drug allergy in children. Results We evaluated a total of 180 suspected drug allergy reactions in 97 children, mainly to antibiotics, non-steroidal anti-inflammatory drugs (NSAIDs) and anticonvulsants. Among all suspected allergic drug reactions, 97 (53.9 %) were immediate type and 83 (46.1 %) were non-immediate type. The average time interval between the reaction and allergologic work-up was 5 months. Drug allergy confirmation rates were 30.1 % for beta-lactams, 27.2 % for non-betalactams, 21.1 % for NSAIDs and 30 % for anticonvulsants. Eight of 54 confirmed NIRs showed positivity on immediate skin tests. Regulatory T cells, TGF-β and IL-10 levels were not different between groups with and without confirmed drug allergy. A strong family and personal history of drug allergy were found to be significantly related to the confirmed allergic drug reactions. Conclusion Parent or self-reported drug allergy should be evaluated with a standardized diagnostic work-up before strict prohibitions are made. In addition, family and personal histories of drug allergy were significant risk factors related to allergic drug reactions in children.