I don't want to frighten anyone but just want to add a cautionary note to this.
My daughter (when she lived with us back in 2011) developed what looked like a hard spot/boil type thing at the bikini line area, she has quite serious obesity due to a rare syndrome, and this area was semi covered by her "podge pocket" - the fat apron that hangs down a bin. She is a type 2 on insulin and metformin. I was treating it as a spot, antiseptic cream etc when one morning she said to me "it's turned into a hole" (she has learning difficulties).
To me it looked like whatever it was had burst but she was complaining of soreness so I popped her up to the docs, we were also due to go on holiday. The fairly innocent looking "spot" was actually an ulcer, which had to be cleaned, dried and the dressing changed 3 times daily for over two weeks - that was how long it took to heal, because it was in such an awkward place, a skin crease. Any spots, boils etc that aren't responding to treatment, or anything that seems a bit dodgy, get it checked out.
Better safe than sorry.