Acetyl Salicylic Acid Challenge in Children with Hypersensitivity Reactions to Nonsteroidal Anti-Inflammatory Drugs Differentiates Between Cross-Intolerant and Selective Responders.

BACKGROUND: Hypersensitivity reactions to nonsteroidal anti-inflammatory drugs (NSAIDs) in children are becoming a great concern. Most studies have focused on adults, with noted discrepancies observed in the classification of hypersensitivity reactions to NSAIDs in children when compared with adults. OBJECTIVE: To phenotype a group of children with hypersensitivity reactions to NSAIDs, including paracetamol, and analyze the degree of agreement with the entities reported in adults and how they fit the proposed classifications. METHODS: The study comprised 116 children aged 0.5 to 14 years, with a clinical history indicative of hypersensitivity reactions to NSAIDs. They all underwent a single-blind oral provocation test with acetyl salicylic acid, except in those cases when this was the suspected drug, in which case the challenge was done first with ibuprofen. If positive, cross-intolerance was established and if negative, an oral provocation test with the culprit drug was performed to establish a selective response or exclude allergy. RESULTS: Of the 26% diagnosed as hypersensitive to NSAIDs, 83% were cross-intolerant and 17% selective reactors. The highest significant differences between reactors and nonreactors were observed in the time to reaction after drug intake and the clinical entity (P < .0001), followed by drug involved and age (P < .01). CONCLUSIONS: From the total number of cases confirmed with NSAID hypersensitivity, 83% were cross-intolerant. In cross-intolerant reactions, both cutaneous and respiratory manifestations are common. Acetyl salicylic acid challenge as the first approach proved to be safe and useful to establish the diagnosis.