The more common diseases that cause small bumps on the penis are eczema and scabies, as follows: 1. eczema: belongs to an allergic disease, related to diet and environment, and can usually be treated with topical dinaide cream. 2. scabies: is caused by scabies mite infection, which can lead to small papules on the face or armpits, groin and these folds. Scrotum, penis appear small bumps, and even sinus tracts, usually need to scabies mites this parasite insecticidal treatment, can be applied topically Lindane cream or sulfur ointment, from the neck down all over the body. Do not bathe again on the same day, and bathe again after 24 hours. Therefore, the treatment of scabies mites is a complex problem that requires a comprehensive treatment that takes into account other factors.