Skin Rashes Research Today is a free monthly online journal that collates and summarizes the latest research about Skin Rashes, including details on dermatitis, itches, creams, medication, treatment.

Lack of evidence for allergenic properties of coumarin in a fragrance allergy mouse model.

Vocanson M, Valeyrie M, Rozières A, Hennino A, Floc'h F, Gard A, Nicolas JF

Institut National de la Santé et de la Recherche Médicale (INSERM), U851, IFR 128, BioSciences Lyon-Gerland, Lyon F-69365, France.

BACKGROUND: There is controversy as to whether coumarin, an ingredient in cosmetics and fragrances, is a contact allergen involved in fragrance allergy. We recently showed that the purity of coumarin is a critical parameter for its allergenicity because coumarin preparations containing trace amounts of contaminants induced cell proliferation in the local lymph node (LN) assay whereas pure coumarin did not. OBJECTIVE/METHOD: In the present study, we analyzed the sensitizing properties of coumarin (purity > 99.9) and of dihydrocoumarin (DHC), in a recently developed model of fragrance allergy in mice. RESULTS: DHC was able to prime T cells in LNs draining the sensitization skin site and to induce a typical allergic contact dermatitis (ACD) reaction upon challenge, confirming that DHC is endowed with moderate sensitizing properties. In contrast, no T-cell activation and no ACD responses were obtained following sensitization and challenge with coumarin. CONCLUSION: These results confirm that pure coumarin is endowed with very weak sensitizing capacities, if any, and suggest that the presence of contaminants in coumarin preparations may account for the previously reported allergenic properties of coumarin.

Published 8 November 2007 in Contact Dermatitis, 57(6): 361-4.
Full-text of this article is available online (may require subscription).

© 2004-2008 Skin Rashes Research Today. All Rights Reserved.