Hello,
It can be a boil or a herpes sore. Most individuals have no or only minimal signs or symptoms from HSV-1 or HSV-2 infection. When signs do occur, they typically appear as one or more blisters on or around the genitals or rectum. The blisters break, leaving tender ulcers (sores) that may take two to four weeks to heal the first time they occur.
The only way of ruling it out is by getting yourself tested for genital herpes. Laboratory tests include: culture of the virus, direct fluorescent antibody (DFA) studies to detect virus, skin biopsy, and polymerase chain reaction (PCR) to test for presence of viral DNA. I sincerely advise you to consult a dermatologist and get it ruled out.
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 dermatologist. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.
It could be a breakout due to shaving, which is common in those super sensitive areas. And yes, friction and sweat can further irritate the area.
Itching, burning, tenderness, and sometimes muscle aching or fever accompany a herpes infection. The outbreaks usually form into open sores and can last up to a month to fully heal. If you're concerned, it never hurts to get tested just to be sure.
All the best.