Dermatomyositis as a presentation of neuromyelitis optica spectrum disorder.

This is the first report of neuromyelitis optica spectrum disorder (NMOSD) associated with dermatomyositis (DM).A 40year-old Caucasian female presented with 6months of worsening fatigue, rash, acute weakness worse in her lower extremities, and urinary retention. She was found to have both NMOSD and anti-melanoma differentiation-associated gene (MDA)5 positive DM with interstitial lung disease (ILD). She was treated aggressively and she regained her ability to ambulate.We recommend considering NMOSD in the differential diagnosis of patients with DM and other autoimmune disorders that also present with clinical signs of myelopathy.