Pathology · single question
A patient presents with crepitus in the preauricular (TMJ) region without pain. Rheumatoid factor (RF) is NEGATIVE. What is the MOST likely diagnosis?
Show answer and explanation
Correct answer: C. Osteoarthritis of the TMJ
RF-negative + TMJ crepitus without pain = classic osteoarthritis — the most common degenerative joint disease.
- A. Psoriatic arthritis has specific radiographic patterns and is not the most common cause of RF-negative TMJ crepitus.
- B. Gout in the TMJ is rare; gout causes acute painful flares, not chronic painless crepitus. Confirmed by elevated uric acid and crystal aspiration.
- C. CORRECT. Osteoarthritis = most common degenerative TMJ disorder. Presents with crepitus, decreased range of motion, and condylar bony changes. RF-NEGATIVE (unlike RA). Often painless in early stages.
- D. Rheumatoid arthritis is associated with RF-positive serology in 70-80% of cases. RF-negative finding makes RA less likely.