Drug hypersensitivity in children: a retrospective analysis of 101 pharmacovigilance reports

Our objective was to describe and discuss management of recent cases of drug hypersensitivity in children reported in a pharmacovigilance center. Two pediatric allergy units conducted a collaborative retrospective analysis of 101 adverse drug reactions reported to a regional pharmacovigilance center between January 2016 and July 2019. Time lapse between hypersensitivity reaction onset and allergy consultation varied from 1 month to 12 years. Sixty-two patients (61.4%) presented with immediate reactions, 11 (10.9%) with non-immediate reactions, and 28 (27.7%) had reactions impossible to classify through medical interview. Overall, 92 children (91%) were explored for simultaneously administered drugs. All 113 prick tests were negative, and 2 were uncertain. Among 108 intradermal tests, 2 were positive to penicillin and to an iodinated contrast medium, 105 were negative, and 1 was uncertain. Overall, 129 drug provocation tests were proposed. Nine provocation tests among 80 were positive (11.25%): 6 to penicillin, 1 to sulfonamide antibiotics, and 2 to non-steroidal anti-inflammatory drugs; the remaining 71 were negative. No severe reaction was observed during these tests. Finally, drug allergy was only retained in 11 reported cases (10.9%).Conclusion: These pharmacovigilance reports show the difficulty in defining drug allergy in children only by anamnesis, and that explorations, particularly provocation tests, should take place at a reasonable time lapse after drug hypersensitivity reaction onset. What is Known: • True drug allergy is rarely observed in children. • Absence of full workup leads to falsely labeling children as "allergic." What is New: • Short time lapse between hypersensitivity onset and consultation improves classification of pediatric allergy. • Timely allergy consultations are essential, and tests are useful to confirm or exclude pediatric allergy.