Thanks for your question. Rashes on penis are common which are caused by bacterial infection. They will come and go but to get rid of it permanently and prevent eczema, you must consult a doctor immediately. Symptoms vary from person to person, but generally rashes on penis are associated with red and swollen patches on the penis and may sometimes be very itchy with scaly dry patches causing irritation. Tropical ointments and creams are helpful in controlling these rashes unless they are cause of sexually transmitted disease. To reduce the dryness, you can use moisturizers. Consult a doctor who may prescribe injections also if the rashes are severe. It takes about two weeks to heal up completely, but in case it does not, immediate pathological tests as advised by doctor will be necessary.