Frequency of allergic contact dermatitis to isoeugenol is increasing: a review of 3636 patients tested from 2001 to 2005.
Department of Cutaneous Allergy, St John's Institute of Dermatology, St Thomas' Hospital, London SE1 7EH, UK. white@gstt.nhs.uk
BACKGROUND: Isoeugenol is an important fragrance allergen. The cosmetic industry was recommended voluntarily to reduce concentrations of isoeugenol in finished cosmetic products from 0.2% to 0.02% in 1998. It was suspected that this would reduce the incidence of patch test positivity in individuals undergoing routine patch testing after approximately 2-3 years (the Dillarstone effect). OBJECTIVES: To review our patch test data since the change in practice by industry, to see if there has been an observable decrease in isoeugenol contact sensitivity. METHODS: We retrospectively analysed all subjects patch tested to isoeugenol 1% pet. in the St John's Department of Cutaneous Allergy over a period of 5 years, commencing 3 years after the changes. RESULTS: We identified 3636 subjects, 97 of whom were positive for isoeugenol. Year-on-year incidence shows an increasing trend, with an overall incidence of 2.67%. Using the exact Cochran-Armitage test, this ascending trend is statistically significant (P = 0.0182). Seventy-two of 97 isoeugenol-positive subjects were also positive to fragrance mix I. Other fragrances positive in these 97 patients included Myroxylon pereirae (30%), Evernia prunastri (22%) and eugenol (15%). CONCLUSIONS: We suspect that the increasing trend may be due to allergen substitution with compounds chemically related to isoeugenol, or which hydrolyse to isoeugenol itself.
PMID: 17573874 [PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov/pubmed/17573874?dopt=AbstractPlus
