Tea tree oil is a topical treatment that is often used to help treat acne and fungal skin problems. Tea tee oil is only for the skin -- it should not be swallowed or used on the eyes. Allergic reactions are possible; tea tree oil may irritate eczema. Because there is not enough research to determine conclusively its benefits or side effects, you should use caution when using tea tree oil and should avoid it during pregnancy. Follow the links below to find WebMD's comprehensive coverage about how tea tree oil is used, risks and benefits, and much more.