J C:
If your bellybutton is an "innie," you have a sac inside which doesn't let air in and drainage out. Try gently cleansing the area as best you can and applying a cotton ball to "wick out" moisture. Then apply 1% hydrocortisone lotion (OTC). Try this twice a day for a week. If you can, shine a heat lamp on the navel for a few minutes after one of the washes.
If that fails, see the dermatologist.
Good luck.
Dr. R