Abstract Background Chronic rhinosinusitis (CRS) is classified into CRS with nasal polyps (CRSwNP) and CRS without nasal polyps. Endotypes of CRS are divided into type 2 and non-type 2, according to the predominant inflammatory markers of the sinonasal tissues. Tissue biopsies from nasal polyps can help establish the diagnosis of type 2 disease and direct the treatment plan. Patients and methods This is a prospective study which included 60 Egyptian patients with CRSwNP refractory to medical treatment. All patients underwent functional endoscopic sinus surgery. Tissue and serum eosinophilia were assessed. Results Tissue eosinophilia, indicating type 2 disease, was found in 43 patients. Elevated serum eosinophils were present in only 30% of them. Conclusion Seventy-two percent of Egyptian patients, referred to the authors’ institute for surgery for chronic rhinosinusitis with polyps, had type 2 disease as evidenced by high tissue eosinophil count. Serum eosinophilia was found to have a sensitivity of 30% and a specificity of 65%, thus the authors recommend using tissue eosinophilic count for determination of type 2 disease.
Sabaa et al. (Thu,) studied this question.