The Candy Smell Test: A New Test for Retronasal Olfactory Performance

Objectives: To develop and validate an olfactory test kit suitable for children and adults based on retronasal smelling of aromas combined with a sweet taste. Moreover, to explore the age limit at which olfactory testing is feasible and to extend the normative database for the validated Sniffin' Sticks test regarding children of younger ages. Study Design: Randomized three-way crossover study in healthy children and adults. Methods: The newly developed Candy Smell Test (CST, 23 aromatized sorbitol candies) was presented using a four-alternative, forced-choice procedure. First, 353 healthy subjects (230 children and 123 adults) were investigated in three separate sessions with the CST and the validated Sniffin' Sticks (composed of odor threshold, discrimination, and identification tasks). Both tests were then compared in 124 patients with olfactory disorders. Results: Test-retest reliability showed good reproducibility of the data obtained with the CST on 2 days (r(287) = 0.75, P < .001). Test results correlated significantly with the Sniffin' Sticks score (r(366) = 0.84, P < .001), although the CST proves to be much easier. The age limit for obtaining valid data was 7 years for both tests. The cutoff limit for the CST scores to separate normosmics from dysosmics was a score of 16 or less out of 23. Anosmia (cutoff score <= 13) was detected with a sensitivity of 94% and a specificity of 83%. Conclusions: The CST is an easy-to-use, reliable, and fast test of retronasal olfactory performance suitable for the screening of smell function in children above the age of 6 years and adults.