Background: Short-term exposure to odours, also called "olfactory training" has been shown to improve olfactory function in healthy people but also in people with olfactory loss. Aim of this single center, prospective, controlled study was to investigate the change of olfactory function following twice-daily, short-term exposure to 4 odours over a period of approximately 12 weeks.
Material and methods: We compared odour identification abilities and odour thresholds between an olfactory training group (TR group) and a group that did not perform such training (noTR group). Participants exposed themselves twice daily to 4 odours ("rose", "eucalyptus", "lemon", "clove"). Olfactory testing was performed before and after the training period using the "Sniffin' Sticks" test kit (odour identification plus odour thresholds).
Results: At baseline the two groups were not significantly different in terms of age and measures of olfactory sensitivity. The TR group performed significantly better for odour thresholds for all 4 odours compared to the noTR group after 12 weeks of olfactory training. Also, with regard to odour identification the TR group outperformed the noTR group. No significant differences were found for diary-based intensity ratings.
Conclusion: Repeated exposure to odours seems to improve general olfactory sensitivity in children.