Allergic Bronchopulmonary Mycosis Caused by Schizophyllum commune Successfully Treated With Mepolizumab

Allergic bronchopulmonary mycosis (ABPM) is a complication of bronchial asthma (BA) and can lead to lung damage and respiratory failure. The standard treatment for ABPM is steroid therapy. Nonetheless, this treatment increases the risk of infections and osteoporosis. Alternative therapies include immunomodulatory biologics and mucus plug removal by bronchoscopy. This report describes a case of a 70-year-old man diagnosed with BA in 2014 and treated with inhaled corticosteroids/long-acting beta-agonists, which were later discontinued for unknown reasons. He was presented to our department with a BA attack, including wheezing and desaturation. Computed tomography and laboratory examinations suggested ABPM; the patient underwent mucus plug removal. The final diagnosis was ABPM, and steroids and itraconazole were initiated. However, BA symptoms did not improve, and the mucus plug and desaturation persisted. Mepolizumab (100 mg/month) subcutaneously cleared the plug and improved BA. This case demonstrates that mepolizumab can treat patients with ABPM and refractory BA.