Sweet's syndrome associated with Mycobacterium avium infection

A 68-year-old woman presented with a 3-month history of nontender, erythematous nodules on the right side of the neck. Subsequently, tender, circinate erythematous plaques appeared on the limbs, accompanied by peripheral leucocytosis. A biopsy specimen obtained from an erythematous plaque revealed diffuse infiltration of neutrophils in the dermis. Treatment with prednisolone improved the erythematous lesions, but upon tapering of prednisolone, numerous areas of indurated erythema with pustules recurred on the face and back accompanied by high fever. Computed tomography of the lung revealed multiple lesions. A smear of gastric juice contained acid-fast bacilli that were identified as Mycobacterium avium by DNA-DNA hybridization. Treatment with multiple antibiotics did not result in a favourable response of the M. avium infection, and dome-shaped, subcutaneous abscesses developed on the limbs and trunk. Sweet's syndrome may thus occur in association with nontuberculous mycobacterial infection.