Yeast Infection - An overgrowth of fungus, also known as candidiasis, that causes a red rash on the penis and itching and/or burning on the tip of the penis; it is more common in uncircumcised men. Balanitis - Swelling of the tip/head or foreskin of the penis. Bacterial overgrowth in the area results in an infection. May 1, - But on your penis? It can happen, and many things can cause it. A rash can show up as red, itchy patches on the tip of your penis or on the Balanitis · Drug Rash.