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.