Dear members,
Below are brief summaries of 3 recent studies examining ingredients in henna, complimentary hotel products and allergen sensitisation in woodworkers as well as a case report on a ‘hidden allergen’ in baby wipe product.
Consumer Risk in Henna Use: Labeling, Ingredients, and Allergen Disclosure
Bouchelkia I, Alam Z, Annamalai A, Verma KK, Tarbox MB, Desai SR, Bhatia N. Consumer Risk in Henna Use: Labeling, Ingredients, and Allergen Disclosure. Int J Dermatol. 2025 Nov 21. doi: 10.1111/ijd.70165. Epub ahead of print. PMID: 41273067.
This study looked at 36 henna products marketed to U.S consumers and found that PPD was only disclosed in 11% of items examined. Many products were marketed with “natural/organic” claims, with incomplete ingredient lists. Of those where PPD was declared, a recurring excipient triad of tartaric acid, sodium sulfite and cellulose binders were present. Most items provided vague or absent patch-test instructions and explicit adverse reaction descriptions were rare. Although European cosmetic standards generally require clearer labelling of known sensitizers and more explicit safety information than current US regulations, this study highlights the need for clinicians maintain a high index of suspicion for henna-related ACD, routinely screen for recent henna exposure, and counsel patients that “natural” labelling does not ensure safety.
Epidemiological Comparative Study on Contact Sensitisations in Woodworkers With Occupational Dermatitis: Patch Test Data of the Information Network of Departments of Dermatology, 1999 to 2023.
Heizmann L, Schubert S, Bauer A, Becker D, Brockow K, Dickel H, Kränke B, Lang C, Oppel E, Wagner N, Weisshaar E, Wilfinger D, Brans R; IVDK. Epidemiological Comparative Study on Contact Sensitisations in Woodworkers With Occupational Dermatitis: Patch Test Data of the Information Network of Departments of Dermatology, 1999 to 2023. Contact Dermatitis. 2025 Nov 12. doi: 10.1111/cod.70041. Epub ahead of print. PMID: 41224355.
This large IVDK analysis spanning 24 years (1999-2023) examined 471 woodworkers with occupational dermatitis (OD). Allergic contact dermatitis was the most frequent diagnosis (32.5%), with frequent involvement of the hands (63.5%) and the face (8.5%). Sensitisation to epoxy resins was significantly greater compared to woodworkers without OD (sensitisation frequency 5.5% versus 1.3%). Despite colophonium similarly frequently testing positive (5.3% vs 1.9%), this did not reach significant threshold. As airborne ACD from colophonium in sawdust has been reported, the authors considered this as probably contributary to those with facial dermatitis.
Other allergens in affected woodworkers included: Myroxylon pereirae (6.9%), methylisothiazolinone (5.9%), and methyldibromo glutaronitrile (5.6%). Propolis was the only significantly more frequently positive allergen compared to non-woodworkers with OD (5.6% versus 2.5%). These findings highlight the importance of including baseline, resin/glue and plant-based series, considering airborne allergic contact dermatitis and promoting suitable personal protective equipment.
A Cross-Sectional Study of Contact Allergens in Hotel Personal Care Products in Canada, the United States and Europe.
Viltakis V, Kirchhof MG. A Cross-Sectional Study of Contact Allergens in Hotel Personal Care Products in Canada, the United States and Europe. Contact Dermatitis. 2025 Nov 21. doi: 10.1111/cod.70057. Epub ahead of print. PMID: 41267567.
This cross-sectional study analysed ingredient lists from 270 complimentary hotel personal care products (shampoos, conditioners and body washes) from 90 hotels across Canada, the United States and Europe, identifying presence of American Contact Dermatitis Society (ACDS) core allergens. Fragrance was almost ubiquitous across all regions (96.7–100% of products), but preservatives showed marked geographic variation. MCI/MI was a common allergen in US (40%) and Canadian (47.8%) hotel products compared to only 4.4% of European products (p<0.0001). DMDN hydantoin, a formaldehyde releaser, was detected in approximately one in seven products in US/Canada but was not present in any European products. More stringent regulation in Europe has resulted in decrease in ACD to MCI/MI and MI, in comparison to North America. Travellers should be alert to differences in product ingredients in different regions.
Axillary Contact Dermatitis in an Adult Caused by Hexamidine Diisethionate From Baby Wipes Labelled “Pure Water”.
Domingos-Ancement EE, Misery L, Deydier N. Axillary Contact Dermatitis in an Adult Caused by Hexamidine Diisethionate From Baby Wipes Labelled “Pure Water”. Contact Dermatitis. 2025 Nov 19. doi: 10.1111/cod.70055. Epub ahead of print. PMID: 41261938.
This case report describes a rare instance of axillary and facial allergic contact dermatitis in a 51-year-old man caused by hexamidine diisethionate in baby wipes marketed as “pure water”. Standard patch testing was negative for hexamidine, but a repeated open application test (ROAT) with the wipes was positive on day 3. This case report highlights that marketing claims do not always match product ingredient lists and that hexamidine diisethionate can be present in baby wipes.