[A CASE OF SEVERE ASTHMA WHO REQUIRED A SWITCH OF FOUR BIOLOGICS: DIFFERENTIAL RESPONSES ON UPPER AND LOWER AIRWAYS].

At the time of writing of this manuscript, four biologics were clinically available for treatment against severe asthma. The choice of four biologics has been taking into account of the results of several type 2 inflammationrelated biomarkers, and the comorbidities of asthma, such as eosinophilic chronic rhinosinusitis, allergic rhinitis, and atopic dermatitis.In this study, we have experienced a case of severe asthma complicated by eosinophilic chronic rhinosinusitis and eosinophilic otitis media, resulting in the use of four biologics, and we observed differential response of upper and lower airways. As a clear algorithm has not been established for the use of four biologics, our experience of this case would provide important lesson for considering the therapeutic strategies against severe asthma.