Allergic contact dermatitis to cosmetics containing Melaleuca alternifolia(tea tree oil)

Introduction. Melaleuca alternifolia is a coniferous tree found in tropical regions, the needles contain an essential oil that is used in medical and cosmetic products. The essential oil contains turpentines (limonene, alpha- pinene, phellandrene) that are potentially allergenic. Patients and methods. In 1997, 1216 patients were patch tested in our derma toligic unit. Fourteen of them tested because of eczema used products conta ining tea tree oil. The patients used creams, hair products and essential o ils containing Melaleuca alternifolia for cosmetic reasons and to treat ski n affections. They were patch tested for a standard panel of allergens, top ical emulgators, perfumes, plants, topical medications, metal, gloves, topi cal disinfectants and preservatives, dental products and rubber derivatives . Products containing Melaleuca alternifolia were tested concentrated or di luted. Results. We report on 7 cases of patients with an allergic contact dermatit is due to tea tree oil. Two of them also exhibited From a delayed type IV h ypersensitivity towards fragrance-mix or colophony suggesting the possibili ty of cross reaction or an allergic group reaction caused by contamination of the colophony with the volatile fraction of turpentines. Discussion. The allergic potential of low concentrations of Melaleuca alternifolia is pres umed to be low on healthy skin. Photoaged Melaleuca alternifolia must be co nsidered to be a stronger sensitizer.