Stop using any new soaps, lotions, detergents, perfumes, or cosmetics
Gently wash the area with lukewarm water and a mild, fragrance-free cleanser
Pat the skin dry; do not rub
Apply a cool compress for 10–15 minutes at a time
Use a fragrance-free moisturizer or plain petroleum jelly
Apply 1% hydrocortisone cream in a thin layer if the rash is itchy or inflamed
Take an oral antihistamine such as cetirizine or diphenhydramine if itching is severe and you can take it safely
Wear loose, breathable clothing
Avoid scratching, heat, sweating, and hot showers
Keep the area clean and dry
If the rash is from a known trigger, avoid that trigger immediately
Seek urgent medical care if you have trouble breathing, swelling of the face or lips, fever, blistering, severe pain, or the rash is rapidly spreading