Lin RY, et al. - Given the utility of intravenous mepolizumab use in non-asthma eosinophilic disorders, researchers focused on the effectiveness of the subcutaneous asthma dosing of the drug for eosinophilic pneumonia, and here report the case of a middle-aged female suffering from eosinophilic pneumonia, for which she had repeated hospitalizations from 2007 through 2010. Chronic eosinophilic pneumonia and chronic asthma was indicated on a lung biopsy in October 2010. The patient also had chronic sinusitis. No improvement was caused by omalizumab administered for 1 year. She was started on mepolizumab 100 mg subcutaneously every 4 weeks in 2016, which led to symptomatic improvement with decreased oxygen and systemic corticosteroid demands. Before mepolizumab, and while on mepolizumab, peripheral blood eosinophils/mm³ were 237 and 10, respectively. This report indicates that asthma-dosed mepolizumab may elicit a response in parenchymal eosinophilic lung disease. As far as the ability to attenuate eosinophils not only in airways, but also in lung parenchyma is concerned, a benefit over omalizumab may be offered by mepolizumab treatment in asthma where concomitant interstitial disease is suspected.