Unexpected multiple sclerosis‐like symptoms in a rheumatoid arthritis patient treated with Etanercept: A case report

Tumor necrosis factor (TNF) inhibitors are prescribed to treat various autoimmune diseases such as rheumatoid arthritis (RA). Etanercept, a human anti-TNF monoclonal antibody, is a therapeutic option in autoimmune and inflammatory diseases. One of the rare adverse effects of Etanercept is developing central nervous system and peripheral nervous system demyelination however, there is controversy in the cause of it. In this case, we presented a 35-year-old woman with multiple sclerosis (MS)-like symptoms due to taking Etanercept. She had a history of RA since the age of 18 years and was referred to the emergency department with signs and symptoms of para paresthesia, progressive paraparesis of both lower limbs, and urinary retention a year after Etanercept treatment. We discontinued the Etanercept and started Methylprednisolone and Rituximab. Rapid clinical improvement was noted and in the approximately 6-month follow-up, she did not exhibit any neurological worsening. So it is probable that the initiation of Etanercept triggered MS-like syndrome in these patients and healthcare practitioners should take heed of this adverse effect.