Scenario: A 32-year-old nurse presents to your office with a complaint of intermittent episodes of pain, stiffness, and swelling in both hands and wrists for approximately 1 year. The episodes last for several weeks and then resolve. More recently, she noticed similar symptoms in her knees and ankles. Joint pain and stiffness are making it harder for her to get out of bed in the morning and are interfering with her ability to perform her duties at work. The joint stiffness usually lasts for several hours before improving. She also reports malaise and easy fatiguability for the past few months, but she denies having fever, chills, skin rashes, and weight loss. Physical examination reveals a well-developed woman, with blood pressure 120/70 mm Hg, heart rate 82 bpm, and respiratory rate 14 breaths per minute. Her skin does not reveal any rashes. Head, neck, cardiovascular, chest, and abdominal examinations are normal. There is no hepatosplenomegaly. The joint examination reveals the presence of bilateral swelling, redness, and tenderness of most proximal interphalangeal (PIP) joints, metacarpophalangeal (MCP) joints, the wrists, and the knees. Laboratory studies show a mild anemia with hemoglobin 11.2 g/dL, hematocrit 32.5%, mean corpuscular volume (MCV) 85.7 fL, white blood cell (WBC) count 7.9/mm³ with a normal differential, and platelet count 300,000/mm. The urinalysis is clear with no protein and no red blood cells (RBCs). The erythrocyte sedimentation rate (ESR) is 75 mm/h, and the kidney and liver function tests are normal.

Question: What are some prime differences to specify rheumatoid arthritis from osteoarthritis that are seen in this patient?

Potential answers:

A. Bilateral symmetrical swelling, Morning pain and stiffness of less than an hour, larger proximal joints.

B. Small peripheral joints, Unilateral swelling, night pain and stiffness.

C. Morning pain and stiffness of more than an hour, larger proximal joints, no swelling.

D. Small peripheral joints, morning pain and stiffness of more than an hour, bilateral symmetrical swelling.

Answer with rationale: D. Small peripheral joints, morning pain and stiffness of more than an hour, bilateral symmetrical swelling. RA tends to affect smaller peripheral joints such as the fingers, wrists, and ankles whereas OA tends to affect larger, weight bearing joints such as knees, hips, and hands. RA has a specific morning stiffness time of over an hour, whereas OA usually lasts 30 minutes or less. Lastly, RA specifically affects bilaterally and symmetrically, whereas OA is usually unilateral and asymmetrical.

See Chapter 4: Rheumatoid Arthritis in The Color Atlas of Physical Therapy