During the participants’ visit to the occupational health care clinic trained nurses performed a capsaicin test of skin neurosensitivity according to Jourdain (2005). Capsaicin > 95%, article number M2028 from Sigma-Aldrich to 95% ethanol, analytical grade, from Solveco, Sweden, was used. Capsaicin was first dissolved in 95% Ethanol and then prepared in five dilution steps (10) between 3.16 × 10–3% and 3.16 × 10–5% in 10% ethanol. The test procedure was as follow: Participants’ nasolabial folds were first cleaned with 10% ethanol to let them get use to the feeling. Then the most diluted preparation of capsaicin was topically applied on one side with a cotton swab (17 ± 2 µl) together with 10% ethanol in the other fold, as control. If the participant did not feel a difference between the two sides within 3 min the next concentration was applied. The detection threshold was set to the concentration when participants identified a difference between capsaicin and ethanol and the sensation was experienced for more than 30 s. The side for application of capsaicin and ethanol was changed between each step and participants did not know on what side capsaicin was applied (Jourdain et al. 2005). All tests were performed by the same trained personal.