- One of the most common causes of armpit rashes is a fungal infection. Candida yeast lives on skin, but in some people, candida overgrows, especially in moist areas like the armpits. A solution of water and tea tree oil kills the fungus and allows the rash to heal. Mix one part tea tree oil with one part oil and apply to the rash with a cotton ball twice a day. Do not apply undiluted tea tree oil to the skin, as this can cause irritation. To keep the rash from returning, keep the area dry with cornstarch. Make sure to thoroughly dry the underarm area after bathing and after strenuous exercise.
- People with sensitive skin can develop heat rashes. These rashes are characterized by small, red bumps. Staying out of the heat is the only way to prevent a heat rash, but if you've already developed a rash, dusting the area with cornstarch powder is a good way to sooth the area and fight the rash. Do not apply ointment as this seals in the heat and can make the rash worse.
- Many rashes are actually chafed areas. If you underarm is chafed, allow the skin to heal by exposing it to as much air as possible. Do not wear tight-fitting clothes. Clean the area with castille soap and keep dusted with cornstarch or kaolin clay powder. Itching and pain can be soothed with a tea tree oil solution. Candula can also be applied to help sooth the irritation.
