Non-invasive bioengineering methods in an intervention study in 1020 male metal workers: results and implications for occupational dermatology.

BACKGROUND Measurements of transepidermal water loss (TEWL) as an indicator of skin barrier function and colorimetry for quantifying erythema have been recommended for monitoring persons at risk of occupational hand dermatitis. OBJECTIVE This study examines the practicability and usefulness of biophysical measurements at the workplace. PATIENTS/MATERIAL/METHODS: A sample of 1020 male metal workers was enrolled; 800 participants were followed up for 1 year. TEWL results and colorimetry (a* value), respectively, were used as effectiveness outcomes, comparing the findings in the four study arms (skin care, skin protection, both combined, and control group). RESULTS At 1 year follow-up, the TEWL was slightly but significantly lower in the group of participants randomized for application of barrier cream alone, indicating a protective effect. However, addressing both the individual absolute change of a* value and the differences of TEWL (delta-TEWL) of the dominant hand over the study period, no significant difference was found between the four groups. CONCLUSIONS Dermatological examinations at the workplace cannot be replaced by bioengineering techniques. The supplementary benefit is apparently low, possibly because of difficulties in achieving standardized measurement conditions and other technical reasons.