Severe Measles Encephalitis and Acute Disseminated Encephalomyelitis in an Immunocompetent Japanese Young Male.

Measles encephalitis rarely affects young adults and has no established treatment strategy. This brief report described the rare case of an immunocompetent 30-year-old man with severe measles pneumonia and encephalitis, following the autoimmune disease acute disseminated encephalomyelitis, during a large measles outbreak in 2018 in Japan. With multidisciplinary treatments, including corticosteroids, intravenous immunoglobulins, vitamin A, and therapeutic plasma exchange, the patient was successfully treated. This case provides a new strategy for treating measles encephalitis and its complications during measles outbreak.