Drug Allergy in Children: What is the Actual Frequency of Drug Allergies?

OBJECTIVES: Drug hypersensitivity reactions are immunologically mediated reactions resulting in the production of drug-specific antibodies and/or T-cells and constituting only <15% of all drug reactions. Based on the clinical observations, both patients and their parents refer to any undesirable drug reactions as drug allergy, regardless of whether the underlying mechanism is immunological or not. After allergy examinations, only a small percentage of the patients who were reported positive for drug reactions based on their clinical history are actually confirmed to have hypersensitivity. This study aims to determine the actual frequency of drug allergies in children, the drugs that cause the most common allergies in patients with a complaint of drug allergy and evaluate the accompanying demographic and clinical features. METHODS: The study evaluated data from a total of 266 patients (ages of 0–18) with suspected drug allergy during a 3-year period. Twenty-four patients with doctor-diagnosed drug-related anaphylaxis and 85 patients who did not accept diagnostic tests were excluded from the study and the study continued with a total of 157 patients. The allergy work-up consisted of in vivo and in vitro tests, in accordance with the recommendations of the ENDA/EAACI guidelines. RESULTS: Data from a group of 157 patients (M [54.6%]; F [45.4%]) were retrospectively analyzed. Beta-lactams (BLs) were the most common drugs involved in the reported clinical history followed by non-steroidal antiinflammatory drugs (NSAIDs). Allergic reactions occurred on the median 1st day (min: 1-max: 8) after drug intake and were most frequently observed as urticaria (55.3%). Immediate reactions (IRs) were observed in 53.5% and non-IRs in 46.5% of the patients. CONCLUSION: Our data demonstrated that only 15.5% of patients confirmed to be positive to allergy during testing which is in line with the data in the literature. An allergy work-up is mandatory for excluding suspected hypersensitivity.