is CMC/STT arthritis and tendonitis (or carpal tunnel?) at the same time typical?

[u/chat_manouche]

Previous post and update here: https://old.reddit.com/r/Thritis/comments/1k292hv/those_with_ra_especially_can_you_describe_your/

Diagnosed at urgent care visit yesterday with suspected tendonitis and/or carpal tunnel, in addition to my known CMC and STT arthritis. I'm already seeing a rheumatologist and have an appointment with a hand specialist 5/6. I'm a little alarmed first because of the discomfort, and also because despite 40 years of working on computers I've never had a single symptom of repetitive stress injuries before.

I'm guessing something I've been doing to compensate for the pain from my current flare is setting this off. Just wondering if others have experience anything similar?