Eosinophilic Granulomatosis with Polyangiitis Complicated by Eosinophilic Chronic Rhinosinusitis Successfully Treated with Combination of Mepolizumab and Dupilumab.

A 50-year-old man with a history of bronchial asthma was admitted to our hospital with peripheral neuropathy, sinusitis, and eosinophilia. The patient was diagnosed with eosinophilic granulomatosis with polyangiitis (EGPA). The symptoms partially improved with a combination of prednisolone and mepolizumab. However, nasal mucosal biopsy revealed a complication due to eosinophilic sinusitis. The addition of dupilumab resulted in the improvement of sinusitis. Few reports exist on the combination of these two drugs for EGPA, and no case reports exist on the addition of dupilumab in patients with residual eosinophilic sinusitis after treatment with prednisolone and mepolizumab. This case is valuable for future consideration in cases involving combination therapy.