Rheumatology is quite a nice, contained subject and I recommend learning it alongside dermatology as there is some overlap. I used The Greatest Rheumatology Resource Ever which I think is indeed pretty great, uploaded by some very kind medical students for free.
The videos I made are here:
Rheumatology I: arthritis and arthropathies
Rheumatology II: other rheumatological conditions
The notes I made are here:
Rheumatology 3 – additional notes
