[Allergic contact dermatitis to cosmetics containing Melaleuca alternifolia (tea tree oil)].
BACKGROUND
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.


METHODS
In 1997, 1216 patients were patch tested in our dermatoligic unit. Fourteen of them tested because of eczema used products containing tea tree oil. The patients used creams, hair products and essential oils containing Melaleuca alternifolia for cosmetic reasons and to treat skin affections. They were patch tested for a standard panel of allergens, topical emulgators, perfumes, plants, topical medications, metal, gloves, topical disinfectants and preservatives, dental products and rubber derivatives. Products containing Melaleuca alternifolia were tested concentrated or diluted.


RESULTS
We report on 7 cases of patients with an allergic contact dermatitis due to tea tree oil. Two of them also exhibited from a delayed type IV hypersensitivity towards fragrance-mix or colophony suggesting the possibility of cross reaction or an allergic group reaction caused by contamination of the colophony with the volatile fraction of turpentines.


CONCLUSIONS
The allergic potential of low concentrations of Melaleuca alternifolia is presumed to be low on healthy skin. Photoaged Melaleuca alternifolia must be considered to be a stronger sensitizer.
Dermatologische Klinik, UniversitätsSpital Zürich, Suisse.
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Fritz
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Burg
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Krasovec
D000328:Adult; D000891:Anti-Infective Agents, Local / Q000009:adverse effects* / Q000032:analysis; D000081008:Bicyclic Monoterpenes; D003358:Cosmetics / Q000009:adverse effects* / Q000032:analysis; D053138:Cyclohexenes; D017449:Dermatitis, Allergic Contact / Q000175:diagnosis* / Q000209:etiology*; D005260:Female; D006801:Humans; D006968:Hypersensitivity, Delayed / Q000139:chemically induced / Q000175:diagnosis; D000077222:Limonene; D008297:Male; D008875:Middle Aged; D039821:Monoterpenes; D010328:Patch Tests; D012116:Resins, Plant / Q000009:adverse effects; D020947:Tea Tree Oil / Q000009:adverse effects* / Q000032:analysis; D013729:Terpenes / Q000009:adverse effects / Q000032:analysis
D000891:Anti-Infective Agents, Local; D000081008:Bicyclic Monoterpenes; D003358:Cosmetics; D053138:Cyclohexenes; D039821:Monoterpenes; D012116:Resins, Plant; D013729:Terpenes; D020947:Tea Tree Oil; C013893:rosin; D000077222:Limonene; C005451:alpha-pinene