Hi, I have a small group of painful bumps where my tailbone meets my buttocks. There is no color to them, and when i look in the mirror I don t see anything. Can this be an STD or just a skin condition? I have reason to worry about STD s because I recently had unprotected sex, but I also have eczema and psoriasis on my hips, buttocks, thighs, and ankles. This group of bumps on buttocks has never occurred before and I m really concerned. I noticed in a few days ago and it was followed by swollen pelvic lymph nodes