When I had tenosynovitis the first times, I went to the doctors a lot to ask for help. I got a many treats but nothing helped really. Here is a list of things I tried, maybe they help in your case.
Splint, cast, cortisone injections
Voltaren, Diclofenac, Amitriptyline, Katadolon
Physiotherapy, hand therapy, osteopathy, homeopathy, acupuncture, ultrasound, curd packs
MRT (magnetic resonance tomography), examination of the nerves in the arms, X-ray of the cervical spine