Allopurinol-induced Dress syndrome complicated with pancreatitis and ascites: Always look beyond the skin

A 54-year-old male patient with a history of hypertension for the past two years was admitted to the dermatology department with pruriginous maculopapular skin rash, facial edema, and fever after the initiation of allopurinol for hyperuricemia six weeks previously. Dermatological examination revealed generalized erythema with scales, facial edema, cheilitis, and lymphadenomegaly. Laboratory tests showed eosinophilia at 2850/mm³, increased liver enzymes (alanine aminotransferase at 821 UI/L, aspartate aminotransferase at 258 UI/L, alkaline phosphatase at 278 UI/L), functional renal failure with creatinine at 74.59 mg/dL, and increased pancreatic lipase enzyme at 508 U/L. Abdominal sonography revealed normal renal size and a low-abundance ascites. The diagnosis of Dress syndrome was confirmed based on the diagnostic criteria of the RegiSCAR group. The incriminating drug was interrupted, and the patient received topical treatment, oral corticosteroids at a dose of 1 mg/kg/day, and supportive care, including rehydration. Clinical and biological remission was achieved. DRESS syndrome is a serious adverse drug reaction. Hepatitis is one of the most frequent visceral manifestations, while pancreatitis occurs in < 5% of cases. Allopurinol-induced DRESS syndrome is associated with significant mortality due to systemic manifestations. Judicious use of allopurinol for accepted indications is the only way to decrease the incidence and morbidity caused by allopurinol-induced Dress syndrome.