Thanks for posting your query here.
If the knuckle is very swollen and sore, it could be inflammation or local infection.
I would advise for:
1. Trying pain-killer medicines like Paracetamol/Brufen
2. If possible, massage
with lukewarm water
3. Rest to the local part is equally important (the inflammation may not subside if there is repetitive stress
at the local part)
4. Please see your family physician - If there is an infection, you may need some antibiotics.
Dr Tejas Shah