Melaleuca oil (tea tree oil) dermatitis.
BACKGROUND
Melaleuca oil (tea tree oil) is the essential oil distilled from the leaves of Melaleuca alternifolia Cheel. Tea tree oil is popular for treating various cutaneous maladies.


OBJECTIVE
Our purpose was to determine which constituent compounds of Melaleuca oil are responsible for allergic contact eczema in seven patients who became sensitized.


METHODS
The seven patients were patch tested with Finn Chambers to a 1% solution (vol/vol) of melaleuca oil and 1% solutions (vol/vol) of 11 constituent compounds.


RESULTS
Of seven patients reactive to the 1% melaleuca oil solution, six patients also reacted to limonene, five to alpha-terpinene and aromadendrene, 2 to terpinen-4-ol, and one each to p-cymene and alpha-phellandrene. d-Carvone, an autooxidative derivative of limonene, caused no reactions among the seven patients.


CONCLUSIONS
d-Limonene was the most common allergen causing allergic contact eczema in our patients. Clinicians are likely to see more contact eczema caused by the increasing use of this popular nostrum.
Knight
T E
TE
Division of Dermatology, University of Hawaii, John A. Burns School of Medicine, Honolulu.
Hausen
B M
BM
D000368:Aged; D017449:Dermatitis, Allergic Contact / Q000175:diagnosis / Q000209:etiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010328:Patch Tests; D008517:Phytotherapy; D010938:Plant Oils / Q000009:adverse effects* / Q000737:chemistry / Q000627:therapeutic use; D014197:Trees
D010938:Plant Oils