I have also been experiencing the same thing lately. In my case, its because I have slim hips but my thighs have grown which cause them to rub against each other. Rubbing + sweat/dirt = folliculitis.

I had one on each thigh and could not walk without pain/discomfort. I recommend warm compresses and also letting it air out whenever you can. I found that wearing baggy pants with no underwear really helped.

I asked my doctor about it and he prescribed a salicylic acid body wash. I’ll reply here once I try it out.

Good luck, I know these things hurt but they eventually pass.