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.