Dapsone hypersensitivity syndrome.

We describe a 22-year-old woman with cutaneous polyarteritis nodosa in whom dapsone hypersensitivity syndrome (DHS) developed 5 weeks after initiation of dapsone therapy. She had fever and cervical lymphadenopathy, and later a widespread erythematous eruption studded with pustules developed. She also had liver involvement with mixed hepatocellular and cholestatic features. The patient was treated with prednisone 60 mg daily. Once the patient's liver function normalized, prednisone dosage was reduced by 5 mg weekly. The clinical features and treatment of DHS are reviewed. We encourage immediate discontinuation of the drug in a patient in whom a fever or flu-like illness develops, especially 4 or more weeks after the treatment is started. We also suggest routine thyroid function testing 3 months after recovery because of the possible risk of hypothyroidism.