Thank you very much for the question. Tea tree oil is derived from the leaves of the Melaleuca alternifolia, a plant commonly found in Australia and used by the Australian aborigines. It appears that the leaves were used sometime to make tea and hence the name. It is used regularly as an alternative medicine in a variety of conditions like boils, dandruffs, acne, athletes’ foot and others. Tea tree oil is effective against germs and fungus because of the presence of terpenoids like terpenin-4-ol. It has also been used in allopathic medicine and in the treatment of burns. Studies have shown the cytotoxicity of tea tree oil against human fibroblast and epithelial cells and therefore it has been suggested that tea tree oil should not be used on burn wounds ( see reference below-1). I am not sure if you have used tea tree oil before as some individuals may have allergy to the tea tree oil and present with dermatitis like picture with rashes, itching and blisters or serious allergic reactions rarely. When used in undiluted form it can result in a chemical burn showing redness, skin irritation, itching and blistering.
http://asktheburnsurgeon.blogspot.com/2010/01/management-of-2nd-degree-superficial.html describes in detail the management of 2nd degree superficial burn.
Since you have acne and possibly a higher skin bacterial load the affected site should be watched for any sign of infection and antibiotics may be started if this happens. Once the area heals use a bland skin moisturizer to nourish the new skin and use a sunscreen to avoid pigmentation (darkening) of the new skin from sun exposure. A visit to your doctor will be helpful as this advice is given without actually seeing you in person.
Related articles and sites
1)Allergy to tea tree oil: retrospective review of 41 cases with positive patch tests over 4.5 years.
Rutherford T, Nixon R, Tam M, Tate B.
Australas J Dermatol. 2007 May;48(2):83-7.
2)Does tea tree oil have a place in the topical treatment of burns?
Faoagali J, George N, Leditschke JF.
Burns. 1997 Jun;23(4):349-51.
3)Melaleuca oil (tea tree oil) dermatitis.
Knight TE, Hausen BM.
J Am Acad Dermatol. 1994 Mar;30(3):423-7.