If you are experiencing itching and redness on the penis, it is important to evaluate potential causes such as friction from underwear, changes in underwear material, or using a different hygiene product. It is also important to consider the possibility of a sexually transmitted infection if you have had risky sexual encounters recently. If none of these causes seem likely, a redness on the penis may indicate a yeast infection. In this case, you can visit your local pharmacy and ask the pharmacist for advice on over-the-counter products to help with the infection.