A Preventable Adverse Reaction: Drug Reaction With Eosinophilia and Systemic Symptoms (DRESS) Syndrome Following Allopurinol Use for Asymptomatic Hyperuricemia

Drug reaction with eosinophilia and systemic symptoms (DRESS) is a potentially life-threatening drug-induced hypersensitivity reaction. We report the case of a 36-year-old man who developed DRESS syndrome after starting allopurinol for presumed asymptomatic hyperuricemia. He presented with fever and a widespread rash. Symptoms developed within 10 days of starting allopurinol. Labs showed transaminitis, delayed-onset eosinophilia, and elevated inflammatory markers. Biopsy confirmed a drug-induced hypersensitivity pattern. Of note, serum uric acid was normal on admission to our facility. The patient improved with corticosteroids. This case highlights the need for cautious prescribing and recognition of evolving features of DRESS.