MSK and Rheum - Gout, Pseudogout, Fibromyalgia Flashcards
Gout - what is it?
Gout is a form of arthritis caused by the deposition of monosodium urate crystals in and around the joints, causing them to be hot, swollen and painful
Caused by the precipitation of uric acid crystals within the joint leading to an acute inflammatory response
Gout - what are the causes?
Causes of Gout= DART D- iuretics A- lcohol R- enal disease T- rauma
MEDICATIONS - thiazide diuretics and aspirin
Increased CONSUMPTION of purines - shellfish, red meat, anchovies
Decreased clearance of uric acid - dehydration, excessive alcohol consumption
CKD - unable to excrete uric acid
Obesity and diabetes
Chemo and radiotherapy - increases cell break down
Gout - how does it normally present?
Presents with arthritis of the 1st MTP (metatarsophalangeal) joint
Characterised by sudden, severe attacks of pain, swelling, redness and tenderness
Often base of the big toe joint
Gout - what are the non-modifiable risk factors?
Age >50 years
Family history
Male
Gout - what are the clinical features and does it present symmetrically or asymmetrically?
Presents asymmetrically
- Excruciating, sudden, burning pain in the affected joint
- Swelling, redness, warmth, and stiffness in the affected joint
- Mild fever
- Tachycardia - transient sympathetic response to pain of an acute attack
Gout - how do you diagnose and what do you need to exclude?
Need to exclude septic arthritis
- Arthrocentesis with synovial fluid analysis.
- needle-shaped monosodium urate crystals with negative birefringence confirm gout and differentiate it from pseudogout
- fluid sent for gram stain and culture to rule out septic arthritis - XRAY
Gout - what would you find on XRAY?
NORMAL JOINT SPACE
Lytic lesions in the bone
Punched out erosions - have sclerotic borders with overhanging edges
Gout - what is Gouty tophi?
Gouty tophi - subcutaneous deposits of uric acid affecting small joints and connective tissues of hands, elbows and ears
DIP joints in hands most affected
Gout - what measurement is chronic hyperuricaemia defined as?
Chronic hyperuricaemia: uric acid > 450 µmol/l
Gout - what is the acute attack management?
1st line: NSAIDs (Indomethacin) and Colchicine
- If both contraindicated, use oral prednisolone 15mg/day
- if patient already on allopurinol, continue it
Even though NSAIDs is 1st line, CAN’T GIVE ASPIRIN, as aspirin is a cause of Gout
Gout - which NSAID can you not give 1st line in acute attack gout?
Even though NSAIDs is 1st line, CAN’T GIVE ASPIRIN, as aspirin is a cause of gout
Gout - what is the main side-effect of colchicine?
Diarrhoea
Gout - what is the urate lowering therapy (prophylaxis)?
1st line: ALLOPURINOL, xanthine oxidase inhibitor, initial dose of 100 mg od
Serum uric acid aim of < 300 µmol/l
Don’t start allopurinol until 2 weeks after an acute attack, starting too early may precipitate a further attack
2nd line: FEBUXOSTAT, xanthine oxidase inhibitor, given if allopurinol CI
Gout - what are the lifestyle changes a patient can do?
Reduction of alcohol consumption
Reduction of purine-based foods- meat and seafood
Medications that may cause hyperuricaemia reviewed: Thiazides and loop diuretics, Low dose salicylates, Chemotherapy
Staying hydrated
Losing weight
Pseudogout - what is it?
A crystal arthropathy caused by deposition of calcium pyrophosphate crystals in the synovium
Pseudogout - what are the main risk factors?
Increasing age is a big risk factor
If a patient develops gout under the age of 60, they usually have:
- haemochromatosis
- hyperparathyroidism
- low magnesium, low phosphate
- acromegaly
- Wilson’s disease
Pseudogout - what joints are most commonly affected?
knee, wrist and shoulders
Pseudogout - what is the clinical presentation and features?
Inflammation and pain in one joint, hot, swollen, stiff, painful knee - usually monoarticular arthritis but may be oligoarticular
Can be asymptomatic
Affected joints are acutely inflamed with swelling, effusion, warmth and tenderness
Pseudogout - what is the definitive diagnosis and what do you need to exclude?
Need to exclude septic arthritis
Joint aspirated for synovial fluid
Aspirated fluid will show:
- No bacterial growth
- Calcium pyrophosphate crystals
- Rhomboid shaped crystals
- Weakly Positive birefringent of polarised light (Positive, P, Pseudogout P)
Pseudogout - what is the pathognomonic finding on XRAY
CHONDROCALCINOSIS - appears as a thin white line in the middle of the joint space caused by the calcium deposition
Pathognomonic (diagnostic) of pseudogout
Pseudogout - management?
Symptoms usually resolve spontaneously over several weeks
Symptomatic management involves (as for gout):
- NSAIDs
- If NSAIDs contraindicated, then Colchicine
- If both contraindicated, then oral steroids, or intra-articular injection
What are the shape and characteristics of crystals for gout, pseudogout, osteoarthritis and RA?
Gout- monosodium urate crystals that are needle-shaped that are negatively birefringent under polarised light
Pseudogout- calcium pyrophosphate crystals are rhombic/brick shaped that are positively birefringent under polarised light
Osteoarthritis- calcium phosphate crystals associated with degeneration of cartilage, coffin-lid shaped with no birefringence
Rheumatoid arthritis- cholesterol crystals, these are rhombic/brick-shaped with a negative birefringence
Fibromyalgia - what is it?
Syndrome characterised by WIDESPREAD PAIN throughout body at specific anatomical sites
Fibromyalgia - who does it affect more and at what age?
Affects women more than men
30-50yo
