Pain in the thumb joints can be due to a variety of reasons. It can be early degenerative arthritis of small joints, rheumatoid arthritis, trigger finger or a repeated stress injury to the tendons of the thumb.
Next Steps
1) Contrast bath: Take 2 tubs of water, one hot one cold. insert ur painful hand in the hot tub first for 2 mins. while doing this, open and close the fist of the hand inserted in water. after 2 mins insert the hand in cold water tub for 1 min. repeat the same procedure 3-4 times. follow this regulary twice or thrice a day.
2) Follow up with ultrasound sessions for your thumb with your physiotherapist.
3) Can use a Thumb spica support which will rest the tendon of the thumb if its inflammed and thus reduce pain. It comes in universal size. you can order the same online.