How Can A Lumpy Finger Rash With Itching Be Treated?

I have an itchy bumpy rash under my wedding ring. It comes and goes. I have tried antifungal creams and hydrocortisone creams. It sometimes appears even when I am not wearing my ring. I am a dental hygienist and do wash my hands frequently and wear latex gloves. It is almost like a contact dermititis, and sometimes appears even when I am not working. It appears no place else on my hands.