Eosinophilic pneumonia developed after dupilumab administration in a patient with atopic dermatitis.

A 63-year-old woman with refractory atopic dermatitis started treatment with dupilumab. She developed a cough 4 days later, sputum, and a slight fever 2 weeks later. Laboratory test results showed a blood eosinophil count of 7360/μL. Chest x-ray and computed tomography scan showed infiltrative shadows with surrounding consolidation of both upper lobes. Bronchoalveolar lavage fluid eosinophil count was increased (50.0%), and histopathological findings were consistent with numerous eosinophilic infiltrations. Treatment with prednisolone 30 mg/day (0.5 mg/kg/day) was initiated. Her symptom resolved, and the shadow of the lung fields improved. There have been no reported cases of eosinophilic pneumonia diagnosed 7 weeks after the administration of dupilumab for atopic dermatitis.