23 - Arthritis Diagnosis

Question 1

Which arthritides does morning stiffness occur in and how are they distinguished?

Answer 1

Rheumatoid arthritis

Osteoarthritis

• doesn’t state how long it lasts in RA but it lasts <30mins in OA

Question 2

How is ulnar deviation caused by arthritis?

Answer 2

Inflammation of metacarpophalangeal (MCP) joints causes the fingers to become dislocated
As the tendons pull on the dislocated joints, the fingers tend to drift to the ulnar side

Question 3

Which arthritis is most likely to cause ulnar deviation and why?

Answer 3

Rheumatoid arthritis

- v commonly affects the MCP joints, the inflammation of which is what causes ulnar deviation

Question 4

How to differentiate between rheumatoid arthritis and psoriatic arthritis when presented with a polyarthritis?

Answer 4

Polyarticular psoriatic arthritis would be expected to have associated dactylitis and associated psoriasis - absence = RA