[Ability of smelling is reduced reversibly by acute smoking and permanently by chronic smoking]

Whether smoking affects the sense of smell is in debate. To exclude a bias by presbyosmia, we analyzed the influence of acute and chronic smoking on the ability to smell in young adults.

40 smokers (23 women, 17 men) aged between 18-34 years were included. They smoked in average 19.6 cigarettes per day and had an average of 7.96 pack years (minimum: 2.5; maximum: 25). The sense of smell was evaluated using the Sniffin' sticks© olfactory test-battery in 215 min 5 times. The impact of a 2 h controlled abstinence time and subsequent smoking of a cigarette were measured. 43 never smokers were tested as control group.

Smoking had a 2-fold impact on the sense of smell: there was a reversible impairment after acute smoking and a permanent reduction of olfaction in relation to the pack years. In summary, the young smokers remained normosmic, although they showed significantly worse test results compared to the group of never smokers. The olfactory capacity of different groups of smokers differed up to maximum of 4.5 TDI points (sum of olfactory threshold-, discrimination- and identification-score).

The damage caused by smoking seems to be settled in the border area between norm- and hyposmia. In case of an expert opinion the patient should be asked for the pack years and should keep 2 h controlled smoking abstinence prior to olfactory testing.