Bothersome Inner Thigh Rash

Hello.  I am a 35 year old black male and I have had a rash on my right, inner thigh for the past 6 years.  At first, my left inner thigh had the same condition, but later completely went away.  At times, the rash does not itch or become irritated in any way.  However, other times, it is very itchy and becomes aggrivated when i sweat or take showers.  I have noticed over the years that whenever i happen to take an antibiotic for an illness, the rash almost completely disappears, only to resurface later.  

I want to know what it might be and how to rid myself of it once and for all.  Any advice you can offer will greatly be appreciated.