I Have A Burning Rash Under My Breast. It Hurts And Is Spreading And Burning My Skin. What Can It Be?

This is going to sound strange, but if your breast are on the larger size it could be from the moisture. Say, if you sweat some? I had the same problem, went to the dr. And they said it was a strain of yeast the is from the moisture my breasts collect when I sweat. They make a cream to put on it, but its best to see a dr. For it to make 100% sure what it is. Good luck.

Burning  red under breast

I have red burning marks under one breast. Its very itchy.

I get it too.
I haven't the foggiest what it is, but my mother told me to put some baby powder or some Pena-ten cream under my breast where the pain is and it should go away for a while.
It's do to a lot of sweat.

Wash the affected area with a mild soap and cool water. Dry area thoroughly. Apply one of the following as often as necessary: Corn starch, baby powder with cornstarch, or a topical antibiotic.

Also, wear a bra that breaths such as a cotton bra.