Sweet's syndrome associated with Hashimoto's thyroiditis.

Sweet's syndrome or acute febrile neutrophilic dermatosis is characterised by the abrupt onset of painful erythematous plaques or nodules, pyrexia (>38°F) and histopathologic evidence of a dense neutrophilic infiltrate without vasculitis. It has been reported in association with many diseases, however, its association with Hashimoto's thyroiditis is rare. A 47-year-old Filipino woman with a 30-year history of an asymptomatic anterior neck mass developed painful, erythematous annular plaques on her arms with associated fever.