The relationship between neutrophilic dermatosis of the dorsal hands and sweet syndrome: report of 9 cases and comparison to atypical pyoderma gangrenosum.

BACKGROUND Neutrophilic dermatoses are a collection of diseases with varying presentation unified by clinical and histologic features. Neutrophilic dermatosis of the dorsal hands is a recently described clinical entity and an evolving disease concept. Its relationship to acute febrile neutrophilic dermatosis (Sweet syndrome), pyoderma gangrenosum, and a primary vasculitis has been debated. OBSERVATIONS We present 9 cases (8 women and 1 man) of neutrophilic dermatosis of the dorsal hands, all with consistent histologic features. Two cases had histologic evidence of vasculitis, and 3 had clinical extension of lesions onto the forearms. Most showed fever, leukocytosis, and/or elevated erythrocyte sedimentation rate. Individual cases were associated with leukemia, lung carcinoma, and inflammatory bowel disease. All 9 patients responded to systemic corticosteroid therapy, with additional response to dapsone, methotrexate, and potassium iodide therapies in several cases. Of the 9 patients, 5 showed complete resolution of their skin disease, whereas 4 required ongoing therapy. We assessed the 43 cases previously reported in the literature. CONCLUSION The clinical presentation, laboratory data, histologic features, and response to corticosteroid therapy offer strong evidence that neutrophilic dermatosis of the dorsal hands is a localized variant of Sweet syndrome and is also identical to atypical pyoderma gangrenosum when that condition presents on the hands.