I usaually get them under my breast, my inner theighs, underarms, stomach, and private areas. sometimes the pain of the boils are so bad I have to put bandaids on them so it doesn't rub off on my clothes.
I'm not a doctor, but you might want to look up the condition hidradenitis suppurativa. Wiki has a reasonably informative article about it. It is a chronic condtion that affects the areas of the body with apocrine sweat glands (the armpits, groin and buttocks and under the breasts in women)
I have it very mildly (I only get lesions in my groin but they can last for months) and I have found taking a high dose zinc supplement daily helped heal the last lesion I had, and since then I have had no new ones, when before that I almost always had at least one.
i suffer from them too. It really sucks. Right now, I have one in my pubic hair( right above my right lip), and another on my inner thigh. They pus and bleed, and never go the hell away.
I had a few cut out, in day surgery, over the years.
I wish I knew how to prevent them, the only things I know is to not use oils and lotions on the skin, avoid too much power, and generaly keep things clean and dry.