Fungal infections, including yeast, can grow in the moist area between the foreskin and glans. The solution is washing. Every time you bathe, pull back your foreskin as far as it will comfortably go, and rinse with clear water. Return the foreskin to its normal position.
If the foreskin becomes red and itching, a common cause is a fungal or yeast infection. It is easily treated with a prescribed anti-fungal cream, or at home with liquid acidophilus culture (available in health food stores) applied 6 times daily for 6 days. Stop bathing with soaps and bubble-baths.