Allergic bronchopulmonary aspergillosis complicated by eosinophilic chronic rhinosinusitis successfully treated with mepolizumab

A 67‐year‐old woman was admitted to our hospital because of frequent asthma attacks and refractory chronic rhinosinusitis. She was diagnosed with allergic bronchopulmonary aspergillosis (ABPA) concomitant with eosinophilic chronic rhinosinusitis (ECRS) on the basis of peripheral blood eosinophilia, precipitating antibodies against Aspergillus fumigatus, elevated total serum IgE, pulmonary infiltration, central bronchiectasis, mucoid impaction, and bilateral rhinosinusitis with nasal polyps, which showed remarkable eosinophil accumulation histologically, especially in the ethmoid sinuses. Treatment with mepolizumab, 100 mg every 4 weeks, was initiated for both the ABPA and ECRS. Consistent with the decrease in the peripheral eosinophil count, the asthma and rhinosinusitis symptoms were drastically ameliorated. Not only her airway symptoms but also her exercise tolerance and pulmonary function test results remarkably improved. Mepolizumab therapy enhanced the quality of life for this patient with intractable ABPA and ECRS.