Gout and Pseudogout Flashcards
What is gout?
Chronically high blood uric acid
Crystal arthropathy
Urate crystals are deposited in the joint causing it to become hot, swollen and painful
What are gouti tophi?
Subcutaneous deposits of uric acid
Typically affecting the small joints and connective tissues of the hands, elbows and ears
DIP joints are most affected in the hands
Typical presentation of gout
Single acute hot, swollen and painful joint
Differential important to exclude
Septic arthritis
Risk factors for gout (7)
Male
Obesity
High purine diet (e.g. meat and seafood)
Alcohol
Diuretics
Existing cardiovascular or kidney disease
Family history
Typical joints affected in gout
Base of the big toe (metatarsophalangeal joint)
Wrists
Base of thumb (carpometacarpal joints)
Gout can also affects large joints like the knee and ankle
How are gout and pseudogout diagnosed?
Clinically or by aspiration of fluid from the joint
Excluding septic arthritis is essential as this is a potential joint and life-threatening diagnosis
What does aspirated fluid show in gout?
No bacterial growth
Monosodium urate crystals
Needle shaped crystals
Negative birefringent of polarised light
What does joint xray show in gout?
Punched out erosions
Erosions borders can be sclerotic with overhanging edges
Lytic lesions in the bone
Typically the space between the joint is maintained
Acute management of gout
NSAIDs (e.g. ibuprofen) are first-line
Colchicine second-line -used in patients that are inappropriate for NSAIDs
Steroids can be considered third-line
What is the most common SE of colchicine?
Gastrointestinal upset - diarrhoea
Prophylaxis in gout
Allopurinol - xanthine oxidase inhibitor
- reduces the uric acid level
Do not initiate until acute attack has settled
Lifestyle changes
Losing weight, staying hydrated and minimising the consumption of alcohol and purine-based food
What is pseudogout?
Crystal arthropathy
Calcium pyrophosphate crystals
Calcium pyrophosphate crystals are deposited in the joint - chondrocalcinosis
Typical presentation of pseudogout
Older adult with a hot, swollen, stiff, painful knee
Other joints that are commonly affected are the shoulders, wrists and hips
Can be chronic and affect multiple joints
Can be asymptomatic and picked up incidentally on an xray
What does aspirated fluid show in pseudogout?
No bacterial growth
Calcium pyrophosphate crystals
Rhomboid shaped crystals
Positive birefringent of polarised light
