Gold and white gold wedding bands can contain trace amounts of nickel. This is a very common cause for allergic contact dermatitis. A nickel allergy can develop at any point in life. Even if you weren’t allergic to your wedding band at first, you could have developed a contact allergy over time. It could have caused your skin rash. These rashes can spread to other parts of the hand. They can include nearby fingers or the palms of the hand.
Another possible cause could be a reaction to the buildup of debris, soap, moisture, lotion, or dead skin under the ring. These things can irritate the skin and sometimes cause infections. You would benefit from meeting with an allergist or dermatologist. Patch skin testing can rule out allergic contact dermatitis due to metals such as nickel.