Crystal Arthritis Flashcards
What is crystal arthropathy?
Arthritis caused by crystal deposition in joint lining
What is crystal arthropathy?
Arthritis caused by crystal deposition in joint lining
What can the crystals be made from?
- Urate
- Calcium pyrophosphate
- Hydroxapatite
What makes up the crystals in gout?
Monosodium urate
What do monosodium crystals look like?
Negative birefringent needles
How are the monosodium urate crystals formed in gout?
- Purines are converted to uric acid via xanthine oxidase
- Uric acid is converted to monosodium urate
What is the normal serum level of urate?
0.3mm/L
What happens in the acute inflammation involved in a gout attack?
- Urate crystals activate phagocytes and cause inflammation
How long can it take for tophi to resolve?
Up to 2 years
How long can it take for tophi to resolve?
Up to 2 years
What can the crystals be made from?
- Urate
- Calcium pyrophosphate
- Hydroxapatite
What makes up the crystals in gout?
Monosodium urate
What do monosodium crystals look like?
Negative birefringent needles
When should you consider pseudogout might be metabolic disease?
If presentation is similar but seen in a younger person
What is the normal serum level of urate?
0.3mm/L
What happens in the acute inflammation involved in a gout attack?
- Urate crystals activate phagocytes and cause inflammation
What are Tophi?
They are seen in long term deposition and are onion like aggregates of urate crystals with inflammatory cells
How long can it take for tophi to resolve?
Up to 2 years
What are the crystals made of in pseudogout?
Calcium pyrophosphate crystals
What joints usually present with pseudogout?
Knee > wrist > shoulder > ankle > elbow
How is pseudogout usually discovered?
by accident in other xrays
What things are likely to trigger an acute attack in pseudogout?
- Direct trauma to the joint
- Intercurrent illness
- Surgery
- Blood transfusion
When should you consider pseudogout might be metabolic disease?
If presentation is similar but seen in a younger person
How would you describe the crystals in pseudogout?
Rhomboid shaped and positive birefringent
What is the long term treatment for gout?
Aim - urate <0.3mmol/L
Non pharma - lose weight etc.
Withdraw drugs e.g thiazides
Allopurionol! - xanthine oxidase inhibitor
What is the presentation of gout?
- Hot swollen joints
- Common joints: 1st metatarsal of big toe -
- Pain
- May be polyarticular but typically monoarticular
What is the presentation of psuedogout?
- Normally monoarticular not poly
- Severe pain
- Stiffness
- Swelling
- Fever
- Resolution in 1-3 weeks
What is the presentation of metabolic disease?
- Early onset <55
- Polyarticular
- Frequent recurrent attack
Why would you aspirate the joint?
To rule out septic arthritis
What would you see on the xray in gout?
B - Bony hooks
E - Erosions
T - Tophi
S - Space intact
What would you see in the xray with pseudogout?
Chondrocalcinosis - linear calcification parallel to articular surfaces
What would you see on the U&E for gout?
- Might be normal in an acute attack
- Can be used to exclude a diagnosis if serum uric acid is in the lower half of normal range
What is the acute treatment for gout?
- NSAIDs
- Colchicine
- Corticosteriodss
What is the long term treatment for gout?
Aim - urate <0.3mmol/L
Non pharma - lose weight etc.
Withdraw drugs e.g thiazides
Allopurionol! - xanthine oxidase inhibitor
What is the treatment for psuedogout?
Similar to gout
acute = NSAIDs, aspiration of joint, injection of joint, physio
