Hello,
The symptoms are suggestive of pompholyx. Pompholyx primarily involves the hands and fingers and then may involve the feet. The first stage is acute and presents as itchy blisters on the hands, fingers and toes. Then the chronic stage shows more peeling, cracking, or crusting. Then the skin heals up, or the blistering may start again. The exact cause is not known and excessive sweating can be one of the reasons.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your dermatologist. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.
Do you wear any other metal jewelry? It could be that you're developing sensitivity to metal. A previous boss of mine developed this later in life and could no longer where metal jewelry.
Otherwise, I suspect that the moisture trapped under the wedding ring is causing this isolated incident. Be sure to dry the ring and your finger thoroughly after applying lotions, sanitizers and washing your hands. Hope you see relief soon.