Proven immunologically-mediated drug hypersensitivity in children with a history of multiple drug intolerances.

BACKGROUND: Children may be referred to pediatric allergy clinics for reactions to multiple drugs. Multiple drug hypersensitivity (MDH) is defined as immunologically-mediated hypersensitivity to 2 or more chemically different drugs. OBJECTIVE: The aim of this study is to report the allergy workup results of children who had a history of potential hypersensitivity reactions to 2 or more unrelated drugs. METHODS: This study was conducted in the Pediatric Allergy and Immunology department of our hospital. Children who described hypersensitivity reactions to 2 or more drugs were included and were evaluated by allergy workup (skin and/or provocation tests) between January 2011 and July 2016. RESULTS: During the study period, 886 children were evaluated for a history of drug intolerance. Of these children, 73 (8.2%) had a history of drug reactions to 2 or more chemically different drugs. The median age of the children who had a history of reactions to 2 or more drugs was 7.8 (min-max: 2.5-16.4) years, and 59% (n = 43) were male. Among the suspected drugs, antibiotics (65.9%) ranked first, and nonsteroid anti-inflammatory drugs (34.1%) were the second. All 73 children were evaluated with skin or provocation tests with the suspected drugs, and MDH was confirmed in only 2 (2.7%) children. CONCLUSION: Multiple drug hypersensitivity is uncommon in children. The incidence and prevalence of MDH may vary with the specific population studied. Evaluating children with a history of MDH, by performing drug hypersensitivity testing, will help avoid the morbidity associated with unnecessary drug avoidance.