I have bacne where my bra lays. i keep them clean and i don't wear it very tight so what's causing it and how do i stop it?

It may not be acne.: Sometimes a contact dermatitis looks like acne.The treatment for that would be to use hydrocortisone cream and consider changing to a different kind of bra.You can also try putting something(cloth or bandage)between the bra and your skin to see if it helps.If it's acne,it may be the perspiration under the bra that's irritating your skin,then try the suggestion above.If still not better,see doctor.