[Unwarranted allergy labels against opioids].

Allergy warnings against opioids are often registered in patient notes which may limit options for pain management. IgE-mediated allergic reactions and anaphylaxis to opioids are infrequent. More frequently, morphine and other opioids cause non-IgE-mediated histamine release leading to milder symptoms which may partly mimic an anaphylactic reaction and cause clinicians to treat it as such. This case report describes a 28-year-old female whose mild reactions were repeatedly misinterpreted as severe allergic reactions, leading to incorrect allergy labels and surgery delay.