###Human: What are the tiny smooth painless bumps on the butt? ###Assistant: Hi. I saw your clinical pictures (attachment removed to protect patient identity). I am very sorry the pictures are bit blurry, but it looks like molluscum. You will have to meet dermatologist because you are saying that they are spreading. Molluscum is also sexually transmitted viral infection. Molluscum is a highly contagious viral infection, presents with pearly white papules (bumps) with a central pit. It can be confirmed by dermoscopic examination. Another possibility is folliculitis in that area, they are usually painful pustules. For more information consult a dermatologist online -->