Histiocytoid Sweet syndrome successfully treated with etanercept.

We report the first case of a 34-year-old woman with histiocytoid Sweet syndrome (HSS) that was successfully treated with etanercept. HSS is a rare histological variant of acute febrile neutrophilic dermatosis that was described by Requena et al in 2005. It is distinguished by dermal infiltration by mononuclear cells with a histiocytic morphology. To date there are three reported cases of the use of etanercept in the treatment of classic febrile neutrophilic dermatosis but none targeting this disease variant. Our patient presented with a 6-month history of scattered erythematous papules on the neck, trunk, and upper and lower limbs bilaterally. Clinical findings and histopathological evaluation were highly suggestive of HSS. After 32 months of refractory disease activity, our patient was initiated on a regimen of etanercept 1 mg/kg subcutaneously twice weekly and topical desoximetasone 0.05% ointment twice daily as required. To date, our patient has achieved 37 months of remission.