2022 Volume 36 Issue 5 Pages 516-521
The detailed mechanism of acetaminophen hypersensitivity remains unclear, but two sets of immunological and pharmacological mechanisms have been assumed. In addition, there are no reports of remission in cases in which an immunological mechanism is assumed without complications of hypersensitivity to other NSAIDs. Herein, we describe two cases of acetaminophen hypersensitivity, with immunological assessment. The first case was a 15-year-old girl. She had developed nausea, vomiting, and high fever after taking 8.5 mg/kg of acetaminophen. The skin test was unevaluable and other tests were negative; however, the drug provocation test (DPT) produced generalized flushing, nausea, and peripheral cold extremities at a total dose of 10 mg/kg, which necessitated an intramuscular adrenaline injection. The other case was an 8-year-old boy who had developed cough and wheals for the first time despite having taken acetaminophen several times before. The skin test was negative, but the DPT produced nasal obstruction, eyelid swelling, and multiple wheals at a total dose of 0.9 mg/kg. Twenty-two months later, he had a negative DPT at a total dose of 14 mg/kg. Even in patients with previously diagnosed acetaminophen hypersensitivity, the DPT should be considered after some time due to the possibility of remission.
