Hello, My boyfriend 20 years old He has developed these

Patient: Hello,My boyfriend 20 years old. He has developed these scabs on his penis, buttox, abdominal area and upper thighs. He says Just the ones on his abdominal region and thighs itch. I am looking for some information to help him.A few weeks ago, he was handling fiberglass at work. Never washing his hands, he then decided to masterbate. (He’s not that bright)I am not sure if that could be a possible reason for these bumps or it is something else.