Myasthenia Gravis Complicated by Eosinophilic Granulomatosis with Polyangiitis: A Case Report

A 55-year-old woman with a history of allergic sinusitis was being administered cyclosporine for ptosis and diplopia due to myasthenia gravis since age 46 years. She developed painful dysesthesia that began in her feet and later spread to her palms, leading to difficulty in walking. Eosinophils were markedly increased in the peripheral blood. Nerve conduction studies revealed mononeuritis multiplex. Nerve biopsy showed the infiltration of eosinophils in the superior neurovasculature. Based on these findings, eosinophilic granulomatous polyangiitis was diagnosed. Methylprednisolone pulse therapy was followed by oral prednisolone. Two weeks after treatment, the patient could do normal daily activities without assistance. In patients with myasthenia gravis having a history of allergic diseases, considering EGPA as a complication and monitoring prior changes in blood data are necessary for early detection before apparent tissue damage.