Olfactory Performance Assessed for Children by the Combined Testing of Olfactory Threshold and Odor Identification

Background It is important to use odor threshold and odor identification (OI) tests to evaluate children's olfactory function. However, there is a lack of Chinese normative data obtained in a large sample for these tests. Objective The purpose of this study was to provide normative data for Chinese children regarding olfactory threshold (OT) and OI tests, as well as combined scores, which help clinicians distinguish between normosmia and dysfunction in clinical diagnosis. Methods Olfactory testing was conducted using the “Sniffin’ Sticks” OT test and the 12-item “U-Sniff” OI test; TI score was calculated as the sum of OT and OI scores. The data were collected from 450 children between the age of 5 and 17 years. In line with previous studies, participants were divided into subgroups regarding their age: (1) 5-8 years, (2) 9-11 years, and (3) 12-17 years. Results Normative data for OT, OI, and TI score were established across different age groups. Age was found to have a significant impact on OT, OI, and TI performance. Elder children achieved higher scores compared to younger children ( P < 0.001 for all). Conclusion This study offers normative data for evaluating the sense of smell in Chinese children using both the OT and OI tests. These tests can help differentiate between a normal sense of smell and dysfunction. Combining these two tests can provide a comprehensive evaluation of the olfactory function in children.