There are a number of common reasons that can cause red bumps on your penis. Your bumps might be caused by a harmless condition such as eczema, lichen planus, lymphocele, dermatitis, or condom-induced allergies, etc. However, occasionally they can indicate a significant health problem like sexual transmitted diseases, hence i would recommend you to consult a primary health care physician. There is no need to panic, all the above mentioned medical conditions can be cured completely.