Pain in all fingers between the joints?

For the past 7 years I’ve had pain 24/7 in all of my fingers. It’s essentially the area of the distal phalange. No pain in the joints at all. Just a dull ache 24/7 and flares up and gets worse whenever it wants to. Pain flares up no matter what im doing. Doesn’t matter if im using my hands or not. Flare ups last normally 1-2 days before it returns to just a normal dull ache. The flare ups are a lot worse and more frequent during the summer. That being said, direct heat does help.

I have been tested twice for RA and a bunch of other rheumatology related bloodwork and nothing came up. I have had 2 hand x rays as well as a CT and MRI of both hands and no results either.

Recently within the past year it’s gotten worse. It’s spread to my thumbs which have not hurt at all for the past 6 years. The same bone area as well as the outside of my thumb, and the webbing between my thumb and pointer finger hurt now as well. My elbows have started to hurt whenever i bend them.

It’s getting hard for me to grip things due to the pain. I can’t really use a fork and knife to cut things. I have trouble driving since it hurts to wrap my fingers around the steering wheel.

Recently the past two days both of my hands have been weak. I’m having trouble gripping things. Not because of the pain but my fingers are just weak.

I have absolutely no clue what this could be and neither do any of the doctors I’ve seen. When this first started i saw a rheumatologist and a neurologist, both said there was nothing wrong. Since then I’ve seen a new rheumatologist as an adult who also can’t figure out what it is. I was given a prescription for prednisone to see if that would help and it did not. Just wondering if anyone else has experience anything similar.