title: Allergy to tea tree oil: retrospective review of 41 cases with positive patch tests over 4.5 years.
abstract: Tea tree oil use is increasing, with considerable interest in it being a 'natural' antimicrobial. It is found in many commercially available skin and hair care products in Australia. We retrospectively reviewed our patch test data at the Skin and Cancer Foundation Victoria over a 4.5-year period and identified 41 cases of positive reactions to oxidized tea tree oil of 2320 people patch-tested, giving a prevalence of 1.8%. The tea tree oil reaction was deemed relevant to the presenting dermatitis in 17 of 41 (41%) patients. Of those with positive reactions, 27 of 41 (66%) recalled prior use of tea tree oil and eight of 41 (20%) specified prior application of neat (100%) tea tree oil. Tea tree oil allergic contact dermatitis is under-reported in the literature but is sufficiently common in Australia to warrant inclusion of tea tree oil, at a concentration of 10% in petrolatum, in standard patch-test series. Given tea tree oil from freshly opened tea tree oil products elicits no or weak reactions, oxidized tea tree oil should be used for patch testing.
authors.affiliation: The Skin and Cancer Foundation, Melbourne, Victoria, Australia.
authors.forename: Tim
authors.initials: T
authors.lastname: Rutherford
authors.forename: Rosemary
authors.initials: R
authors.lastname: Nixon
authors.forename: Mei
authors.initials: M
authors.lastname: Tam
authors.forename: Bruce
authors.initials: B
authors.lastname: Tate
mesh_terms: D000328:Adult; D000368:Aged; D000485:Allergens / Q000009:adverse effects*; D003358:Cosmetics / Q000009:adverse effects*; D017449:Dermatitis, Allergic Contact / Q000175:diagnosis* / Q000209:etiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010328:Patch Tests / Q000379:methods*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D020947:Tea Tree Oil / Q000009:adverse effects*; D014739:Victoria
chemical_list: D000485:Allergens; D003358:Cosmetics; D020947:Tea Tree Oil