Classification of eCRS: Based on disease outcome or normal range?: Comment on Toro et al.

Undoubtedly, there is a lack of unanimous histopathologic criteria to classify eosinophilic chronic rhinosinusitis (eCRS) worldwide. We read with great interest the recent constructive systematic review by Toro et al.(1). The authors stretched out the current knowledge on the methods of classifying eCRS to determine an optimal cut-off point. While the authors are to be congratulated for their comprehensive overview, a point regarding the disease recurrence as the most relevant parameter to divide eosinophilic and noneosinophilic inflammation in chronic rhinosinusitis (CRS) should be discussed. In order to contribute to an evidence-based standardization of cut-off point to classify eCRS, we would like to share our considerations and approaches in this comment.