What Causes a Rash in Your Armpit? An armpit rash is more common than you might think. Your armpits probably come into contact with more chemicals each day than most other parts of your body.

Armpit rashes often develop due to allergic reactions, infections, and chronic conditions. Rashes are common under the arms because the skinfold creates a warm, moist environment. Additionally ...

An armpit rash is often caused by irritation from sweat, friction, soap, or dryness. It could also be an allergic reaction to fragrances or propylene glycol (a deodorant ingredient). Other causes ...