Severe Mononeuritis Multiplex due to Rheumatoid Vasculitis in Rheumatoid Arthritis in Sustained Clinical Remission for Decades

Rheumatoid vasculitis (RV) usually occurs in patients with refractory rheumatoid arthritis (RA). An 80-year-old woman was transferred to our hospital because of muscle weakness and paresthesia in all 4 limbs. She had been diagnosed with RA 30 years ago and achieved sustained clinical remission. At presentation, polyarthritis and drop foot were observed, and rheumatoid factor was prominently elevated. A peripheral nerve conduction test revealed mononeuritis multiplex in her limbs. We suspected that RV had developed rapidly despite RA having been stable for many years and started immunosuppression therapy with steroids combined with azathioprine. The treatment prevented worsening of muscle weakness and paresthesia.