Gout Flashcards
What is gout?
A crystral arthropathy
Disorder of the purine metabolism
Characterised by raised uric acid levels and deposition of urate crystals in joints and other tissues (e.g., soft CT or the UTI)
What is pseudogout?
Crystalline, inflammatory, asymmetrical mono-/oligo-/polyarthritis
Involves the peripheral joints due to deposition of microscopic crystals (CPPD) and more commonly in the elderly
What is the incidence of gout?
1.77 per 1000 person years
What is the prevalence of psuedogout?
7-10% in over 60s (UK)
Which sex does gout affect more?
M > F (4.3:1)
What is the typical age of onset for gout?
30-40 years
Which sex does pseudogout affect more?
F and M equally affected
Which continents have a higher prevalence in gout?
Oceania, North America and among indigenous populations e.g., Māori, Aboriginals, and Inuit
What are the risk factors for gout?
Beer (i.e., alcohol)
Meat, seafood (i.e., high protein diet)
Fructose
FHx
Medications
Obesity
List the medications that can increase the risk of gout
ACEis
β blockers
Ciclosporin
Diuretics
Pyrazinamide
Tacrolimus
Ritanovir
Lead exposure
What are the risk factors for pseudogout?
Elderly
If young:
-hyperparathyroidism
-haemochromatosis
What is the pathogenesis of gout?
Increase uric acid level
Leads to formation of monosodium urate crystals
What is the pathogenesis of pseudogout?
Formation of calcium pyrophosphate dihydrate crystals (CPPD)
Deposits in joints causing inflammation and pain
TRUE OR FALSE
Gout has positively birefringent crystals
FALSE
Has strongly NEGATIVE birefringent needle like crystals
It is pseudogout that has POSITIVE birefringent rhomboid shaped crystals
Which joints does gout normally affect first and in what order?
- Big toe
- Knee
N.B – smaller joints first then larger joints
Which joints does pseudogout normally affect first and in what order?
- Knee
- Wrist
- Ankle
- Elbow
- 2nd and 3rd MCP
- Shoulders
What would you expect to see on examination of someone with gout?
Joint is:
Erythematous
Swollen
Hot
Tophi in joints - normally not painful,
What would you expect to see on X-ray for gout?
Acute = normal
Chronic = well-demarcated erosion
What blood test would you do for gout and what would you expect to see?
- Hyperuricaemia - (serum uric acid >6.8 mg/dl (404 µmol/l))
- Raised WBC
- Raised ESR
What are the diagnostic tools that can be used for gout?
Arthrocentesis with synovial fluid analysis – 1st line
Blood tests – serum uric acid levels, dual energy computed tomography (DECT)
X-ray of affected joint
What is the management of gout?
1st line = treat pain + inflammation – NSAIDs (continue until 1-2 days after initial acute episode) /colchicine. Can also give short course of oral corticosteroids
Reduce inflammation – steroids which can be injected into joint space if NSAIDs or colchicine are not tolerated or are ineffective
Lifestyle change – reduce meat and alcohol consumption to reduce uric acid consumption
Prophylactic medications – allopurinol and febuxostat which inhibit xanthine oxidase an enzyme that is involved in uric acid production
What follow-up should be arranged for people with acute gout in primary care?
Review after 4-6 weeks to:
- measure serum urate levels
- explain what gout is and that it is lifelong, risk factors, how to manage flares, lifestyle changes, where to find information
- review meds (see which ones could be causing the gout)
For someone with HTN on diuretics what should you do to manage their gout?
Consider changing to an alternative antihypertensive provided their BP is well controlled
For someone with HF on diuretics what should you do to manage their gout?
Continue diuretics during an acute attack
For someone with HF on NSAIDs to manage pain from gout, how should they be monitored?
Monitor renal function closely
What is the prognosis of gout?
Acute attacks usually self-limiting – resolves completely in 1-2 weeks without treatment
Attacks recur in 62% of people within a year
Recurrent attacks and chronic gout lead to progressive joint damage, pain and disability
How should pseudogout be managed?
Pain -NSAIDs/colchicine
Reduce inflammation – intrarticular steroid injections/systemic steroids
Cannot use allopurinol/febuxostat as pathogenesis is different to gout
What is the prognosis of pseudogout?
Acute attacks usually resolves within 10 days
Some patients may go on to develop progressive joint damage with functional limitation
What other DDx should be considered for gout?
Septic arthritis
OA
RA
Reactive arthritis
Bursitis, cellulitis, tenosynovitis
Trauma
Haemochromatosis
What other DDx should be considered for pseudogout?
Acute gout
Septic arthritis
OA
RA
What steroid is given for acute gout, how long for and at what dose?
Prednisolone
30-35mg OD
3-5 days
N.B. this is an off-label use of oral corticosteroids
Sources
https://bestpractice.bmj.com/topics/en-gb/13
https://cks.nice.org.uk/topics/gout/management/acute-gout/
https://patient.info/doctor/calcium-pyrophosphate-deposition-including-pseudogout-pro
What is the typical dose of colchicine given in acute gout?
500 micrograms
2–4 times a day until symptoms relieved
maximum 6 mg per course
do not repeat course within 3 days.
What are the side effects of colchicine?
Common/very common
- abdo pain
- N+V
- diarrhoea
Frequency unknown
- agranulocytosis
- alopecia
- bone marrow disorders
- GI haemorrhage
- kidney injury
- hepatic injury
- menstrual cycle irregularities
- myopathy
- nerve disorders
- rash
- sperm abnormalities
- thrombocytopenia
