Gout and Pseudogout Flashcards
What is Gout?
A crystal arthropathy associated with chronically high uric acid levels.
What are gout tophi?
Subcutaneous deposits of uric acid, typically affecting small joints and connective tissue in hands, elbows and ears.
How does gout present?
A single acutely hot, swollen and painful joint.
What is an important differential of gout?
Septic arthritis
Which joints are most commonly affected by gout?
- Metatarsophalangeal joint of the big toe
- Carpometacarpal joint (base of the thumb)
- Big joints e.g. knee and ankle
What are the risk factors for gout?
- Male sex
- Obesity
- High purine diet e.g. meats and seafood
- Alcohol
- Diuretics
- CVS or Kidney disease
- Family history
How is gout diagnosed?
- Clinically
- Aspiration of fluid from the joint (excluding septic arthritis)
What will aspiration show in gout?
- No bacterial growth
- Needle shaped crystals
- negative birrefringente of polarised light
- Monosodium urate crystals
What will an XR show in gout?
- Joint space is maintained
- Lytic lesions on the bone
- Punched out erosions
- Erosions can have sclerotic borders with overhanging edges
How is acute gout managed?
- NSAIDs (first line)
- Colchicine (second line)
- Steroids (third line)
When is colchicine used?
- Inappropriate for NSAIDs e.g. renal impairment, significant heart disease
What is a notable side effect of colchicine and how is it fixed?
- GI upset (diarrhoea)
- Dose dependent so reducing dose should resolve
What is the prophylactic treatment for gout?
Allopurinol
How does allopurinol work?
Xanthine oxidate inhibitor, works by reducing the serum urate level
What lifestyle changes protect from gout?
- Weight loss
- Hydration
- Minimise alcohol
- Reduce purine based foods e.g. meats and seafood
What is pseudogout?
Crystal arthropathy, but with calcium pyrophosphate crystals
What is pseudogout also called?
Chondrocalcinosis- calcium deposition in the joint
How does pseudogout present?
- Older adult
- Hot, swollen and painful joint
- Typically affects the knee, but also shoulders, wrists and hips
- Can also be asymptomatic/incidental on XR
How is pseudogout diagnosed?
- Exclude septic arthritis
- Tends to be milder than gout
- Definitive diagnosis is by aspirating synovial fluid
What will aspiration show in pseudogout?
- Calcium pyrophosphate crystals
- Rhomboid crystals
- Positive birefringent of polarised light
What will and XR show in pseudogout?
- Chondrocalcinosis (calcification of the chondral surface)
- Thin white line in the middle of the joint space
- LOSS (Same as OA)
What is the pneumonic LOSS for a joint XR?
Loss of joint space
Osteophytes
Subarticular sclerosis
Subchondral cysts
How is pseudogout managed?
- Asymptomatic cases need no treatment
- Symptoms themselves usually resolve over several weeks
- NSAIDs
- Colchicine
- Joint aspiration and steroid injection
- Oral steroids
