Odor identification performance in children aged 3–6 years

Background While valid and reliable olfactory tests have been developed for children aged >5 years, olfactory testing has not systematically been evaluated in younger children. The aim of this study was to evaluate the reliability and validity of the “U-Sniff” odor identification test in children aged 3–6 years. Methods We included 160 healthy children (age range 3–6 years) and 14 congenitally anosmic children. Participants were investigated in two identical sessions. The “U-Sniff” test was used to evaluate olfactory function. A picture identification test (PIT) and the Kasel-Concentration-Task (KKA) were administered to identify factors influencing odor identification performance. Results Age significantly influenced odor identification performance, with older children achieving higher scores. PIT and KKA scores correlated positively with odor identification scores. The “U-Sniff” test demonstrated a high test–retest reliability ( r 160 = 0.75, p < 0.001). It was possible to distinguish between healthy and anosmic children by means of “U-Sniff” scores starting at age 4 years with high sensitivity (79–93%) and specificity (88–95%). Conclusions The “U-Sniff” test is feasible for children starting at age 3 years. In children aged ≥4 years, it is a reliable and valid method to distinguish between normal olfactory function and anosmia. Impact Olfactory testing is reliable and valid starting at an age of 4 years. The study adds a systematic evaluation of olfactory testing in young children. Results of this study are especially interesting for clinicians in the diagnosis of olfactory dysfunction.