What Do Itchy, Recurring Lumps On Buttocks With Pimple Inside Vaginal Wall Suggest?

I continuously have lumps on my buttocks which itches at times and or feels as if something is crawling on me. The lumps or bumps seems irritated and spreads then reduces and may be gone for a while but come back. I sit in the tub to ease some of the itch and irritations. I put creme on it which gives a couple of hours relief. What is this or how can I prevent it for reoccurring. I also have something like a pimple on my inside vagina wall which reacts the same way with other aggravated systems.