Yes it can. Its used on all kinds of cuts scrapes and burns and cold sores. Fair warning, it burns. Frankly I cant stand the smell, but if you can get past that its a good alternative to pharmaceuticals.
I use tea tree oil for keeping the dreaded nits at bay on my kids - one squirt on their hair before they go to school, no nits making the return journey home. If you are using it for medicinal purposes make sure you get Melaleuca Alternifolia oil - that one is the one that means business!
It's outstanding!! was used by the Aussies in ww2 before the advent of penicillin, it has the ability to penetrate thru the skin and fight infections.. very well!!..
It's right up there with the Aloe plant for natural goodness!!! but it only comes from one plant and it grows in swamps and I'm not sure but I always thought it only grew in Australia...
I have been using this for years, I use a product called tri-care from farnam on my animals, the ingredients are amazing and include tea tree oil - I know may ranchers locally that use this on themselves - I have a turkey with about 40 stitches in it from a raccoon attack (the raccoon didn't give it the stitches, I did) I hold this product responsible for the continued survival of this animal. I have dozens of success stories applying veterinary care to my animals utilizing MY common sense(ones that are not worth the expense of a vet and would consequently be destroyed/eaten).
A member of my family is strangely susceptible to topical yeast / fungal infections, after many visits and $$$ to the doctor I thought, an ounce of prevention is worth a pound of cure, I instructed this family member to throw out all of the lotions and soaps that they were using for skin management and told them to make sure that every soap and lotion they used had tea tree oil in it, they have not had another case in years, ostensibly ELIMINATING the need for doctors care.
This is not a miracle cure for the new millennia, this is a "miracle cure" from the old, (e.g. silver).
In the last 100 years, civilization has become so accustom to Pharmacia that they have forgotten the tried and true of the old. in some areas of medicine, it seems science is fighting a losing battle trying to out-engineer the SYMPTOMS caused by the micro-evolution of bacteria / disease, I am afraid that science itself is going to inadvertently create a super disease (hmm...I think I heard that from them).
Keep in mind, it is not worth it to try to replace a doctor with tea tree oil, or any other magic potion - if a wound is properly dealt with at the time of injury, there won't be the need for possible staph laden doctor visits and subsequent antibiotics / antifungal. If you feel as though you can outsmart your doctor, you need to find a smarter (more open minded?) doctor.
I got thrush from taking antibiotics. I washed my mouth out with tea tree oil and a few drops of water 3x a day and all went away. the australian tea tree oil book says that (OK ladies this is for us) to take a douche with tea tree oil and also you can put it in your bath water for yeast infections.
I use TTO in a poultice with lavendar oil, eucalyptus leaves, camomile flowers and seaweed anytime I have stiches to help control secondary infection and cut down itching. The one time I didn't use it was when I had staples, and durned if I didn't get an abcessed infection. YMMV.