NASAL EOSINOPHIL COUNT AND PERCENTAGE IN CHILDREN WITH ALLERGIC RHINITIS

Abstract

Introduction The total count and percentage of eosinophils in a nasal smear sample are useful for diagnosing allergic rhinitis. Although some studies have evaluated the presence of nasal eosinophilia for diagnosing allergic rhinitis, the use of this criterion is not sufficiently investigated. In addition, no study has determined the correlation between eosinophil count and percentage in sample nasal smears. Therefore, this study aimed to investigate the correlation between nasal eosinophil count and percentage in patients with rhinitis. Methods This was a retrospective cohort study of patients with a clinical history of rhinitis, under 19 years of age, examined at an outpatient clinic of a tertiary referral hospital in Korea, between January and August 2017. Nasal smears of patients were obtained by swabbing the nasal inferior turbinate 3–4 times with a cotton swab. The sample was then placed on a glass slide and stained with Giemsa stain. All specimens were examined by the same pathologist, who was blinded to the clinical history of each patient. Results A total of 106 pediatric patients underwent nasal smear examinations. There was a positive correlation between the nasal eosinophil count and percentage in patients with rhinitis. Y = 0.768 × X + 0.280 (Y = eosinophil count; X = eosinophil percent). The cut-off value was based on the nasal eosinophil count (10 cells/high-powered field) or a nasal eosinophil percent >10% in the patients with allergic rhinitis. Conclusions The nasal eosinophil count and percentage can be useful tools for the diagnosis of allergic rhinitis in pediatric patients.