It can be due to Rheumatoid arthritis. Get your rheumatoid factor checked first along with
uric acid level. If increased or RA +ve, go to a rheumatologist for pain relief as well as a physiotherapist for decrease in pain and swelling , increase in strength and range of motion .
Next Steps
Go to a physiotherapist.. Ultrasonic therapy +TENS +Heating therapy +some strengthening exercises+stretching exercises will be helpful for sure.
Health Tips
At home.. Rest +hot water fomentation +pain killer gel +no long posture assumption +frequent movements of hand, arm and fingers+avoid cold exposure .