Acute febrile neutrophilic dermatosis (Sweet's syndrome) and the related conditions of "bowel bypass" syndrome and bullous pyoderma gangrenosum.

Since Sweet's initial description of eight patients, the concept of acute febrile neutrophilic dermatosis has evolved and changed. We have expanded it to include patients with bullous pyoderma gangrenosum, bowel-bypass syndrome with or without the bypass, the vesiculopustular eruption or ulcerative colitis, and possibly even typical pyoderma gangrenosum. A variant of acute febrile neutrophilic dermatosis in which acute myeloid leukemia is present has been reported and seems identical to bullous pyoderma gangrenosum. Although no clear pathogenesis has been demonstrated, studies of the bowel-bypass syndrome have implicated immune complex disease. Therapy with prednisone is usually effective, but numerous other anti-inflammatory agents have been used effectively.