Sweet's syndrome (SS) is a neutrophilic dermatosis characterized by an abrupt onset of painful erythematous cutaneous lesions that have a neutrophilic infiltrate typically located in the papillary dermis. Fever and an elevated neutrophil count can accompany the cutaneous manifestations. Systemic corticosteroids are the mainstay of treatment, although steroid-sparing agents are frequently coadministered or substituted. We report a case of a white man in his 60s who had a 5-year history of SS refractory to various conventional treatments. Rituximab, a potent B-cell–depleting anti-CD20 monoclonal antibody, was initiated and resulted in a dramatic improvement.
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