Scabies is a skin condition caused by mites (small insects) which dig into the skin and make it itch. It is spread by close physical contact like sex, holding hands, sharing towels/beds/clothes. If you are HIV positive your immune system, which fights infections, is weaker, so more mites can live on your body causing scabs/crusts to form. Scabies can be treated with special creams available at a clinic. All members of your household must be treated to prevent re-infection.
Attribution: Straight Talk Foundation