Trimethoprim-sulfamethoxazole-associated acute febrile neutrophilic dermatosis: case report and review of drug-induced Sweet's syndrome.

Sweet's syndrome, or acute febrile neutrophilic dermatosis, is characterized by fever, neutrophilia, and painful erythematous cutaneous plaques that contain a dense neutrophilic dermal infiltrate. Although the disorder is usually idiopathic, patients with drug-induced Sweet's syndrome have been described. We describe a 50-year-old woman with trimethoprim-sulfamethoxazole (TMP-SMX)--induced Sweet's syndrome and review the features of the 13 previously reported patients with drug-induced Sweet's syndrome. All patients had fever, painful skin lesions (most commonly on the upper extremities), and a biopsy-confirmed neutrophilic dermatosis. All patients also exhibited a temporal relationship between drug administration and clinical presentation and between drug withdrawal and healing. In patients with drug-induced Sweet's syndrome, neutrophilia is often absent.