Severe relapse after cessation of immunosuppressive therapy in a patient with co‐occurrence of neuromyelitis optica spectrum disorder and Sjögren's syndrome: A case report

Neuromyelitis optica spectrum disorder (NMOSD) is a group of autoimmune disorders characterized by inflammatory involvement of the optic nerve, spinal cord, and central nervous system. NMOSD is often associated with other autoimmune disorders, including Sjogren's syndrome (SS). While NMOSD typically occurs at a peak in young or older individuals, the coexistence of NMOSD and SS in a youngster is rare. Here, we presented a case of a 14-year-old girl with NMOSD and SS who responded well to immunosuppressive therapy but experienced a severe relapse after discontinuation of therapy. We described the clinical course of a case over 8 years, underscoring the importance of long-term treatment for NMOSD and SS. This case, along with the review of relevant literature, will raise awareness of this type of disease and facilitate early diagnosis and treatment to avoid serious sequelae.