Few cases of Sweet's syndrome have been reported in patients with Behçet's disease.

A 47-year-old woman with five year history of oral and genital ulcers that had not been investigated previously was admitted for an eruption of tender, erythematous, vesicle-like papules over the face, neck, palms, and legs. She reported polyarthralgia and weight loss of 6kg over the previous month. At admission, she had a fever of 38.5°C and conjunctivitis. Joint tenderness to mobilization without evidence of synovitis was noted. Laboratory tests showed inflammation and leukocytosis (12.5×10⁹/L) with 74% neutrophils. The skin biopsy was typical for Sweet's syndrome, and the pathergy test was positive. Glucocorticoid therapy 40mg/day and colchicine were effective in alleviating the manifestations.

Overlap exists between the clinical manifestations of Sweet's syndrome and Behçet's disease. Data from the literature suggest that Behçet's disease may be among the conditions that underlie Sweet's syndrome.