What are pimple like sores on the inner thigh and under arms (armpit/side chest area)?

Posted by confused09

I've always had these pimple like sores on my inner thighs that I would get in the summer, or when it was warm and my thighs would rub together. After I started dating my boyfriend I got the same type bumps on my armpits and my side where my bra would go. Could this be an std symptom? something else? Is there anyway to tell how long you've had an std if you have one? please help!