[Steroids-Resistant EGPA-Induced Neuropathy with Acute Disease Progression: How to Use Mepolizumab as Novel Targeted Agent].

Eosinophilic granulomatosis with polyangiitis (EGPA), an antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis, is a systemic vasculitis syndrome involving inflammatory damage of predominantly small vessels. Initial treatment is extremely important because the peripheral nervous system is a major target organ that depends on long-term clinical outcomes. Moreover, detailed neurological observations are necessary during the remission period. Although corticosteroids and cyclophosphamide are used as the first-line therapy, intravenous immunoglobulin is beneficial for patients with steroid resistance. Mepolizumab administration is preferentially considered for patients with EGPA, which is refractory to treatment with corticosteroids, cyclophosphamide, and intravenous immunoglobulin.