Suggest Treatment For Skin Rashes On The Buttocks

Well, I m sort of embarrassed to talk about this, but for a few years now, I ve been getting this sort of rash-like lesion on my buttocks, or in my anal crevice, every time I start my menstrual period. The thing starts off as a really irritable itch in the spot where it will develop; then, days later, it will develop into a sort of lesion. It s not a boil as I know what boils look like. This is something totally different than a simple boil. The lesion is not very painful at all; just very itchy and annoying. When I touch it, it feels sort of like a swollen insect bite, and when I look at it, it appears purplish in color and sort of pock marked. I really can t tell what it looks like, it s hard to describe. Most of the time it appears a week or two before my menstrual period, lasts through the few days, and then afterwards, begins fading away. The next month, it reappears, but not always in the same spot, but always on a buttock or in my anal crevice. I m 46 years old, still have periods every month, but I never had this issue when I was a young girl/woman. I noticed this issue didn t start happening until after I d turned 40 years old. The lesion never spreads after I scratch the itch (I know I probably shouldn t be scratching it) and aside from daily baths in oatmeal powder, I usually use a topical agent on it, like Blue Star ointment or Campho-Phenique (sp). Those products seem to relieve the itch, but they don t remedy the lesion altogether. It s really strange that I m not bothered by these lesions until around the time of my menstrual flow. I m thinking it s hormonal. They appear nowhere else on my body except on my buttocks or in the crevice. There is no puss drainage or odor associated with the lesion. It s really annoying, though ...