Table 1 Main characteristics of participants
From: Optimizing diagnostic tests for persulphate-induced respiratory diseases
|  | Hairdressers (n = 19) | Symptomatic controls (n = 12) | Healthy controls (n = 40) | P valueα |
|---|---|---|---|---|
Mean age, years (SD) | 31 (10.5) | 21 (2.6) | 35 (12.9) | 0.002 |
BMI, mean (SD) | 22.5 (3.8) | 22.4 (3.4) | 24.7 (4.3) | 1.000 |
Sex (% female) | 19 (100) | 7 (58) | 43 | 0.02 |
Smoking status, n (%) | ||||
 Smoker | 7 (37) | 5 (42) | – | 0.79 |
 Never smoker | 12 (63) | 7 (58) | – | |
Atopic dermatitis, n (%) | 3 (16) | 6 (50) | 0 (0) | 0.06 |
Total IgE, mean (SD) | 58.3 (76) | 156.5 (202) | Â | 0.22 |
Atopya (%) | 6 (32) | 10 (83) | Â | 0.009 |
FeNO ≥ 25 ppb, n (%) | 3 (16) | 5 (42) |  | 0.20 |
FeNO ≥ 50 ppb, n (%) | 1 (5.2) | 3 (25) |  |  |
Lung function, mean (SD) | ||||
 % FEV1 | 101.7 (9.7) | 106.6 (14.8) |  | 0.48 |
 % FVC | 105.3 (8.7) | 116.8 (14.1) |  | 0.025 |
 FEV1/FVC | 84.8 (7.6) | 78.9 (6.6) |  | 0.43 |
Methacholine test | ||||
 BHR, n (%) | 5 (26) | 7 (58) |  | 0.13 |
Asthma medication, n (%) | ||||
 None | 12 (63) | 0 (0) |  |  |
 SABA | 3 (16) | 7 (58) |  |  |
 SABA + low dose ICS | 1 (5) | 3 (25) |  |  |
 SABA + medium dose ICS | 1 (5) | 2 (17) |  |  |
 SABA + LABA/ICS | 1 (5) | 0 (0) |  |  |
 SABA + LTRA | 1 (5) | 0 (0) |  |  |
Rhinitis medication, n (%) | ||||
 None | 13 (68) | 2 (17) |  |  |
 OA | 2 (11) | 8 (67) |  |  |
 INS | 1 (5) | 1 (8) |  |  |
 OA + INS | 2 (11) | 1 (8) |  |  |
 OA + antihistamine eye drops | 1 (5) | 0 (0) |  |  |
Work-related symptoms, n (%) | ||||
 Rhinitis symptoms | 1 (5) | – |  |  |
 Asthma symptoms | 1 (5) | – |  |  |
 Both | 17 (90) | – |  |  |
Trigger of symptoms, n (%) | ||||
 Bleaching products | 19 (100) | – |  |  |
 Hair dye | 9 (49) | – |  |  |
 Hair spray | 4 (21) | – |  |  |
 Permanent solution | 3 (16) | – |  |  |
 Perfume | 3 (16) | – |  |  |
Positive stop/resume test, n (%) | 16 (84) | – |  |  |