with "tendonitis" you mean pain similar to "sciatica"? (if you ever suffered from sciatica)
sounds like Peripheral Neuropathy. strange that you don't have other symptoms.
the specialist would be Rheumatolgist / Neurologist
Definitely go see a doctor. It could be carpal tunnel, or it could be another neurological problem. It is good to get it checked out to avoid risking permanent nerve damage.
Well you should make in appointment with a doctor to get that checked out my young cousin had the same symptoms as you but she let it go and know she cant move her hand she has to have some one cut her meat for her like a small child so I would go asap.