Theeboomolie (tea tree oil)

Tea tree oil is an essential oil which is often used for the treatment of minor skin conditions; it may also be present in cosmetics and household products. Prevalences of positive patch test reactions in routine testing have ranged from 0.1% to 3.5% and was 0.9% in a Dutch study. In 30 publications, 90 patients with allergic contact dermatitis from tea tree oil have been described. The sensitizing potential of the oil increases from air exposure by oxidation. The most important allergenic ingredients are ascaridole, terpinolene, Α-terpinene, 1,2,4-trihy-droxymenthane, Α-phellandrene and limonene. The clinical picture of allergic contact dermatitis from tea tree oil depends on the products used. Most reactions are caused by the application of pure oil, while cosmetics containing the oil in 25% of patients. Patch testing may be performed with the patient's product diluted to 5-10% tea tree oil in petrolatum; there is also a 5% oxidized TTO test material commercially available. Co-reactivity to turpentine oil is frequent and co-reactivity to fragrance-mix I, Myroxylon pereirae, colophony, other essential oils or a combination thereof are regularly found.