Allopurinol-Induced Drug Reaction With Eosinophilia and Systemic Symptoms (DRESS) Syndrome: A Case Report and Review of the Published Evidence From India

We report a case of allopurinol-induced drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome in a 58-year-old hypertensive female who developed generalized erythematous, pruritic skin lesions approximately 35 days after initiating allopurinol (100 mg twice daily) for a provisional diagnosis of gout. Dermatological examination revealed diffuse erythematous to hyperpigmented scaly plaques involving the face, trunk, groin, buttocks, and extremities. Laboratory investigations demonstrated marked eosinophilia (30%; absolute eosinophil count of 880 cells/mm³), persistent leukocytosis, transient thrombocytopenia (140,000/mm³), acute kidney injury with elevated blood urea (102-116 mg/dL) and serum creatinine (1.8-3.8 mg/dL), and hepatic dysfunction with elevated alanine aminotransferase (130 IU/L) and alkaline phosphatase (179 U/L). Infectious and autoimmune causes were excluded, and a RegiSCAR score of 7 established a definite diagnosis of DRESS syndrome. Allopurinol was immediately discontinued, and the patient was treated with intravenous hydration, systemic corticosteroids, antihistamines, and supportive care, followed by a gradual tapering of prednisolone. The patient showed complete clinical recovery without recurrence. This case highlights the importance of early recognition of allopurinol-induced DRESS syndrome, prompt withdrawal of the offending drug, timely initiation of systemic corticosteroid therapy, and close monitoring of renal and hepatic involvement to achieve favorable clinical outcomes. It also underscores the value of pharmacovigilance and adverse drug reaction reporting in improving medication safety.