Contact sensitizations in massage therapists with occupational contact dermatitis: Patch test data of the Information Network of Departments of Dermatology, 2008-2020.

BACKGROUND: Massage therapists are particularly exposed to constituents of massage preparations, wet work and mechanical strain and therefore, at high risk to develop occupational dermatitis (OD). OBJECTIVES: To describe the sensitization spectrum of massage therapists with OD. PATIENTS AND METHODS: In a retrospective study, patch test data of patients with OD (128 massage therapists and 24 374 patients working in other professions) collected by the Network of Departments of Dermatology (IVDK, 2008-2020) were analysed. RESULTS: Hand dermatitis (91.4%) and allergic contact dermatitis (34.4%) were common in massage therapists with OD. Most frequent were sensitizations to fragrances/essential oils which were found in 54 (42.2%) massage therapists and thus, more often than in other patients with OD. Concomitant positivity to several fragrances/essential oils was frequent. In 8 (14.8%) of the 54 massage therapists, sensitizations to fragrances/essential oils were not detected with the baseline series, but only with special fragrance series. CONCLUSIONS: Allergic contact dermatitis is common in massage therapists with OD and is mainly caused by fragrances and essential oils. Hence, massage therapists should be aware of this risk. When OD is suspected, not only the baseline series, but also special fragrance series should be patch tested in this occupational group.

The effect of epidermal levels of urocanic acid on 25-hydroxyvitamin D synthesis and inflammatory mediators upon narrowband UVB irradiation.

BACKGROUND/PURPOSE: Urocanic acid (UCA) absorbs ultraviolet (UV)B radiation in the epidermis which may interfere with phototherapy. Therefore, the influence of individual levels of UCA on immune reactivity and vitamin D synthesis induced by narrowband UVB radiation was assessed. METHODS: Twenty-eight subjects with irritant contact dermatitis of the hands were irradiated with suberythemal doses of narrowband UVB radiation on their unaffected lower forearms on three consecutive days. Stratum corneum tape strips and epidermal interstitial fluid (ISF) as well as blood samples were analyzed. RESULTS: Narrowband UVB irradiation led to the conversion of trans-UCA into its cis-isomer in the epidermis. The observed increase in 25-hydroxyvitamin D serum concentrations was inversely correlated with the baseline levels of trans-UCA. Furthermore, UVB irradiation induced significant changes in the levels of CXCL10/IP-10, CCL2/MCP-1, CCL4/MIP-1ß, and the IL-1RA/IL-1α ratio. The levels of IL-1α and CXCL9/MIG showed a trend toward increase. The changes in the levels of inflammatory and immunomodulatory mediators did not depend on baseline levels of trans-UCA. CONCLUSION: The results suggest that epidermal levels of trans-UCA affect vitamin D synthesis, but not cutaneous immune reactivity upon repeated exposure to suberythemal doses of narrowband UVB radiation. However, this requires further exploration.