Gabrielli S, et al. - Hypersensitivity reactions related to acetaminophen usage in adults and children were studied and the prevalence of acetaminophen hypersensitivity in children with a suspected acetaminophen allergy was assessed via a systematic review and a meta-analysis, respectively. More than 25% of the articles reported immediate (within 1 h of exposure) hypersensitivity reactions, while about 25% of the articles similarly reported cutaneous nonimmediate reactions. Steven-Johnson syndrome/toxic epidermal necrolysis, fixed drug eruptions, and cross-intolerance reactions were also reported. The prevalence of acetaminophen hypersensitivity reaction among children undergoing oral challenge was 10.1%.