Co-Treatment with Steroid and Dupilumab for Eosinophilic Chronic Rhinosinusitis after Eosinophilic Pneumonitis Caused by Dupilumab

Eosinophilic chronic rhinosinusitis (ECRS) is a Type 2 inflammatory disease that manifests as chronic inflammation of the paranasal sinus. IL-4/IL-13 receptor monoclonal antibodies (dupilumab) to suppress Type 2 inflammation have become a good treatment option for patients who are refractory to surgery. Most patients respond normally, although significant side effects such as eosinophilic pneumonia may occur, requiring discontinuation of dupilumab. Here, we present a case in which dupilumab administration caused a side-effect of eosinophilic pneumonia. A 65-year-old woman presented with nasal obstruction and olfactory dysfunction due to a nasal polyp. Her symptoms temporarily improved with dupilumab; however, dupilumab was discontinued due to eosinophilic pneumonia. Discontinuation of dupilumab resulted in the rapid resolution of eosinophilic pneumonia and reappearance of nasal polyps. We, therefore, resumed dupilumab treatment in combination with low-dose steroids; eosinophilic pneumonia did not flare up, and the nasal polyps shrank steadily. There is no established treatment strategy in cases where a side effect of eosinophilic pneumonia arises while treating ECRS with dupilumab. Based on the described case, we recommend that a combination of a low-dose steroids and dupilumab be considered as a treatment option to counter the side-effect of eosinophilic pneumonia induced by dupilumab alone.