Stop using any new deodorant, antiperspirant, soap, lotion, or laundry detergent that may be irritating the area
Wash the armpit gently with lukewarm water and a mild, fragrance-free cleanser
Pat the area completely dry after washing
Keep the area cool and dry
Wear loose, breathable cotton clothing
Avoid shaving the armpit until it heals
Do not scratch or rub the rash
Apply a fragrance-free moisturizer if the skin is dry or irritated
Use an over-the-counter hydrocortisone 1% cream for a short period if the rash is itchy or inflamed
Use an over-the-counter antifungal cream if the rash is red, moist, or has a fungal appearance
Use an over-the-counter antihistamine if itching is severe and you can take it safely
Change sweaty clothing promptly
Use a clean towel and do not share towels
Seek medical care if the rash is painful, spreading, oozing, blistering, or associated with fever
Seek medical care if the rash does not improve within 1 to 2 weeks
Seek medical care if you have diabetes, a weakened immune system, or frequent recurrent rashes