Refractory neuro-Sweet disease successfully treated with tocilizumab and mycophenolate mofetil.

Sweet syndrome, or acute febrile neutrophilic dermatosis, is mainly a dermatologic condition presenting with erythematous plaques; however, neutrophils infiltrate multiple systems. Neuro-Sweet disease is a neurological manifestation of Sweet syndrome and a rare cause of recurrent aseptic meningoencephalitis, which needs to be distinguished from neuro-Behçet disease. Although neuro-Sweet disease generally responds well to corticosteroids, relapsing neuro-Sweet disease is not an exceptional case. Herein, we present a case of a 51-year-old male with recurrent encephalitis followed by erythematous plaques. The patient was confirmed as Sweet syndrome based on skin biopsy and showed partial response to corticosteroids. With intravenous immunoglobulin, rituximab, tocilizumab, and mycophenolate mofetil, his neurologic symptoms were fully recovered.