Sweet's syndrome: recurrent oral ulceration, pyrexia, thrombophlebitis, and cutaneous lesions.

We report a case of Sweet's syndrome with recurrent oral ulceration, pyrexia, skin lesions, and migratory thrombophlebitis, with no detectable systemic cause, during a 2-year follow-up. Biopsy examination both of oral lesions and the skin eruption showed a characteristic dense, perivascular, neutrophilic infiltrate in the lamina propria. Laboratory investigations confirmed an inflammatory syndrome with an increased erythrocyte sedimentation rate, but no underlying cause was found. Sweet's syndrome is a rare immunologically mediated condition that belongs to the group of neutrophilic dermatoses that must be differentiated particularly from Behcet's disease. It is characterized by red-brown plaques and nodules that are frequently painful and occur primarily on the head, neck, and upper extremities. Often the patients also have neutrophilia and fever and may have oral ulceration. In approximately 10% of patients with Sweet's syndrome, there is an associated malignancy--most commonly acute myelogenous leukemia--but some cases, as here, are unassociated with detectable malignant or other disease, although the syndrome may precede the onset of definable systemic disease.