Hello,
It can be a small cyst, infected hair follicle, insect bite or some form of clogged pore due to friction rub. Keep the area clean and apply some topical antiseptics. Also wear loose-fitting cotton clothing and use an antibacterial soap or mild soap like dove. Avoid any kind of cosmetics and avoid coarse clothing and wear 100% cotton fabric against your skin and clothing that is free of moisture, dried sweat, chemicals, dirt and other debris. Topical antibiotics such as mupirocin or Neosporin are also useful. In case the symptoms persist then oral antibiotics may be needed. Please consult a dermatologist in that case.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.
go see your doc look up the signs your having