Cheilitis was observed in a 74-year-old patient after use of a new toothpaste which occurred after several weeks despite withdrawal of the paste. Positive patch testing with the toothpaste confirmed suspect contact sensitization. The cause was the main component of the flavour additive i. e. the terpene ketone L-carvone. Due to the characteristic flavour it is contained in many mint and peppermint oils. In this case it also caused the recurrences by sucking of refreshment lozenges. L-Carvone is also contained in most chewing gums and should thus be considered aetiologically in cases of cheilitis and stomatitis.