However, the symptomatic hairdressers had more throat irritation (OR 1.13, CI 95 % −1.12, 1.37; ns) than the pollen allergic women (data not shown). Table 2 Total nasal symptoms per week during the observation period (median; range) in symptomatic check details (S+) and asymptomatic (S−) hairdressers and pollen allergic women (PA)

Study groups S+ n = 17 S− n = 19 PA n = 10 P values S+ ↔ S− S+ ↔ PA S− ↔ PA Week 1 7 (0–18) 0 (0–9) 14 (0–20) 0.001 0.011 <0.001 Week 2 8 (0–16) 0 (0–7) 8.5 (0–21) <0.001 ns <0.001 Week 3 8 (0–18) 0 (0–3) 15.5 (0–22) 0.001 ns 0.001 Week 4 11 (0–25) 0 (0–14) 7.5 (0–19) <0.001 ns 0.001 Blocking, secretion, itching, sneezing. Symptoms caused by present infection are excluded ns non-significant Fig. 2 Nasal symptoms (blockage, itching, sneezing, secretion; Mean) without infection and work days in symptomatic (S+; n = 17) and asymptomatic (S−; n = 19) hairdressers and pollen allergic women (PA; n = 10) Table 3 OR, CI 95 % and P values for nasal symptoms in the symptomatic (S+) and the asymptomatic hairdressers (S−) compared to the pollen allergic women (PA) during the observation period Nasal symptoms S+ n = 17 S− n = 19 P value OR CI 95 % OR CI 95 % S+ S− Blockage 1.23 (0.41–3.70) 0.04 (0.01–0.15) ns <0.001

Itching 0.69 (0.26–1.85) 0.05 (0.01–0.33) ns <0.001 Sneezing 0.30 (0.12–0.74) 0.06 (0.02–0.25) 0.010 <0.001 Secretion 0.52 (0.18–1.52) Protein Tyrosine Kinase inhibitor 0.02 (0.0–0.06) ns <0.001 Exposure Although the S+ group had a tendency to perform more hair treatments such as bleach, high-lifting blond and hair dye than the S− group, the only significant difference was in the use of hair spray (Mean S+ 3.0, S− 2.3; Mean difference −0.569, CI 95 % −0.917 to −0.221; P = 0.001). Within the S+ group, there was a tendency to less numbers of hair treatments

during the last part of the study period (data not shown). There were no significant differences in the type of bleaching powder used such as dust, granules Thymidine kinase and crème, nor the type of hairspray (pump or aerosol www.selleckchem.com/products/BafilomycinA1.html propellant). Local exhaust ventilation was infrequently used in both groups (data not shown). Nasal lavage and specific nasal challenge Inflammatory markers The S+ group increased in ECP during the study period, and the S− group did not. The PA group had a higher level ECP, but no significant increase during the study period was noticed (Table 4). No significant differences regarding Substance P and Tryptase were registered between the S+ and S− groups during the study period. There was no significant difference in tryptase levels before and after the study period in the PA group (data not shown).