Dermatomyositis as a presentation of neuromyelitis optica spectrum disorder.

IMPORTANCE: This is the first report of neuromyelitis optica spectrum disorder (NMOSD) associated with dermatomyositis (DM). REPORT: 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. CONCLUSION: We recommend considering NMOSD in the differential diagnosis of patients with DM and other autoimmune disorders that also present with clinical signs of myelopathy.