Tea tree is a native of Australia. Australian Aborigines used the leaves to treat cuts and skin infections, according to the University of Michigan Health System. They crushed tea tree leaves and applied them directly to the infected area. Tea tree essential oil is produced from the leaves and bark by distillation. It is available as a pure essential oil and is used as an ingredient in many different creams, lotions and ointments. According to the Linus Pauling Institute, tea tree oil is an effective treatment for many skin conditions, such as cold sores, the blisters of shingles and chicken pox, warts, acne and rash.
Apply tea tree oil undiluted to the affected area twice a day. Don't apply undiluted tea tree oil to large areas of skin, advises the University of Michigan Health System, since it can irritate the skin or you could have an allergic reaction to it. If you need to cover a large area of rash, dilute the tea tree oil in an herbal tea such as chamomile and spray it on your skin.
Add five drops of tea tree oil to your bath, up to twice a day for a week.
Add tea tree oil to lotion or cream. Use no more than 5 percent, which means for 8 oz. of lotion you can add 2 1/2 tsp. of tea tree oil.