Osteoarthritis hand DIP vs RA MCP/PIP and psoriatic DIP
How to tell Osteoarthritis hand DIP and RA MCP/PIP and psoriatic DIP apart when a board question makes them look alike.
OA DIP has bony nodes and brief stiffness; RA is MCP/PIP inflammatory erosive disease; psoriatic DIP has psoriasis, nail pitting, and dactylitis.
Side by side
Hand osteoarthritis affects DIP and PIP joints with Heberden and Bouchard nodes, brief stiffness, bony enlargement, and pain worse with use.
RA affects MCP/PIP with prolonged morning stiffness and erosions; psoriatic arthritis can affect DIP with nail pitting, dactylitis, and psoriasis.
OA is degenerative cartilage loss with osteophytes and subchondral sclerosis.
RA is autoimmune synovitis; psoriatic arthritis is seronegative enthesitis and synovitis tied to psoriasis.
DIP osteophytes and Heberden nodes support hand OA.
Anti-CCP and MCP/PIP erosions support RA; nail pitting and sausage digits support psoriatic arthritis.
The trap
DIP disease is not automatically OA because psoriatic arthritis also hits DIP joints.
The repair move
For hand arthritis, combine joint row with stiffness duration and skin/nail clues.
Try a free question
CoreA 64-year-old woman has 5 years of slowly progressive bony enlargement of the distal interphalangeal joints (Heberden nodes) and proximal interphalangeal joints (Bouchard nodes) of multiple fingers. She has brief morning stiffness <30 minutes and pain worse with activity. ESR and CRP are normal. Hand x-rays show joint-space narrowing, osteophytes, and subchondral sclerosis at the DIP and PIP joints. Which diagnosis is most likely?
Show answer and explanation
Answer: A. Osteoarthritis of the hand. Hand OA preferentially involves DIP (Heberden nodes) and PIP (Bouchard nodes) joints with bony enlargement, normal inflammatory markers, brief morning stiffness, and characteristic x-ray findings.
Why the other choices are tempting
- B. RA affects MCP and PIP joints (sparing DIP) with prolonged morning stiffness, elevated inflammatory markers, and marginal erosions.
- C. Psoriatic arthritis has psoriasis, nail pitting, dactylitis, and pencil-in-cup deformities.
- D. Gout has crystal-proven monoarticular flares.
- E. Erosive OA is a subset of hand OA with central erosions giving a 'gull-wing' appearance, but is less common.
Flashcards
Tap a card to flip it.
What nodes support DIP osteoarthritis?
Heberden nodes support DIP osteoarthritis.
What clue supports psoriatic DIP disease?
Nail pitting or dactylitis supports psoriatic arthritis.
Quick answers
What is the fastest way to tell Osteoarthritis hand DIP from RA MCP/PIP and psoriatic DIP?
OA DIP has bony nodes and brief stiffness; RA is MCP/PIP inflammatory erosive disease; psoriatic DIP has psoriasis, nail pitting, and dactylitis.
What is the key clue for Osteoarthritis hand DIP?
Hand osteoarthritis affects DIP and PIP joints with Heberden and Bouchard nodes, brief stiffness, bony enlargement, and pain worse with use.
What is the key clue for RA MCP/PIP and psoriatic DIP?
RA affects MCP/PIP with prolonged morning stiffness and erosions; psoriatic arthritis can affect DIP with nail pitting, dactylitis, and psoriasis.
What is the common trap with Osteoarthritis hand DIP vs RA MCP/PIP and psoriatic DIP?
DIP disease is not automatically OA because psoriatic arthritis also hits DIP joints.