Pseudogout Flashcards
What are the key characteristics of pseudogout
Results from deposits of calcium pyrophosphate crystals in the synovium
In most causes of pseudogout what is the cause?
Idiopathic
How does pseudogout close resemblance to gout?
In both pathophysiology (crystal arthropathy) and clinical features (acute inflammatory arthropathy)
What is the difference between pseudogout and gout?
Pseudogout is caused by calcium pyrophosphate crystals
Gout is caused by urate (uric acid) crystals.
Name some of the risk factors for pseudogout
Advanced age (although can be seen in younger ages who have underlying risk factors)
Injury or previous joint surgery
Hyperparathyroidism
Haemochromatosis (excess iron accumulates)
Hypomagnesaemia (low serum magnesium)
Hypophosphataemia (low serum phosphate)
What joints are most commonly affected in pseudogout
Most often knee, wrist or ankle
Usually monoarticular arthritis but may be oligoarticular i.e. may affect one or more joints.
Is gout monoarticular or oligoarticular?
monoarticular - usually confined to just one joint in early disease
Can be oligoarticular but that is more rare
Gout and pseudogout have very similar symptoms.
How is pseudogout definitive diagnosed?
Definitive diagnosis requires evidence of both:
calcium pyrophosphate (CPP) crystals on synovial fluid analysis
AND
Classical radiographic changes.
What are the characteristic features of calcium pyrophosphate (CPP) crystals on synovial fluid analysis
[CPP crystals are a unique feature of pseudogout]
- weakly-positively birefringent small rhomboid-shaped crystals
- Shape: rhomboid
- Size: small (0.5 - 10 microns)
- Birefringence: weakly positive on plane-polarised light
What is the classic x-ray feature of pseudogout
Cartilage calcification (previously known as chondrocalcinosis)
Thin opaque (white) line in the middle of the joint space caused by the calcium deposition
How are patients with asymptomatic/incidental finding of pseudogout managed?
Do not require management
There is no long term disease management option for pseudogout
How is an acute flare of pseudogout managed?
The majority of acute flares will resolve spontaneously within 7-14 days
Managed usually with a course of NSAIDs or colchicine
Other options include: oral steroids, i ntra-articular steroid injection, and in severe cases joint washout (arthrocentesis)
Urate lowering drugs are used in the management of what type of gout:
a) Gout
b) Pseudogout
a) Gout
Which type of gout is treatable?
a) Gout
b) Pseudogout
a) Gout
Gout is treatable with lifestyle changes and urate lowering drugs.
The acute attacks of pseudogout can be managed however there is nothing that can given long term to prevent recurrent attacks and the joint destruction
