Combination effect of Mepolizumab and Endobronchial Watanabe Spigot (<scp>EWS)</scp> in drug‐induced eosinophilic pneumonia complicated by refractory pneumothorax

Few reports have described the treatment of eosinophilic pneumonia (EP) complicated by refractory pneumothorax. A 62-year-old man with a medical history of ulcerative colitis who was undergoing maintenance treatment presented with fever, cough, and diffuse bilateral consolidation on chest radiography. Laboratory findings showed peripheral eosinophilia, and he was hospitalized with a diagnosis of drug-induced EP and started on corticosteroid therapy. During the course, he developed refractory pneumothorax, and it was difficult to control the air leakage. As it was necessary to control the eosinophilic inflammation and air leakage, mepolizumab, a humanized anti-interleukin-5 monoclonal antibody, and an endobronchial Watanabe spigot (EWS), were introduced. After EWS insertion, the leakage of the refractory pneumothorax disappeared. The patient continued to have no recurrence of EP or pneumothorax after the removal of the EWS. The combination of mepolizumab and an EWS may be effective in cases of EP complicated by refractory pneumothorax.