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Year 3 Medicine Block > Rheum- Gout > Flashcards

Flashcards in Rheum- Gout Deck (18)
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1
Q

What is gout?

A
  • microcystal synovitis
2
Q

What type of cyrstals do you get in gout?

A
  • deposition of monosodium urate monohydrate in the synovium
  • Needle shaped negatively bifringent
3
Q

What are causes of gout? / RFs?

A
  • chronic hyperuricaemia
    Decreased excretion of uric acid
  • drugs- diuretics
  • CKD
  • Lead toxicity
    Increased production of uric acid
  • myeloproliferative/lymphoproliferative disorder
  • cytotoxic drugs
  • severe psoriasis
4
Q

What is Lesch- Nyhan syndrome?

A
  • hypoxanthine-guanine phosphoribosyl transferase (HGPRTase) deficiency
  • x-linked recessive therefore only seen in boys
  • features: gout, renal failure, neurological deficits, learning difficulties, self-mutilation
5
Q

How does gout present?

A
  • episodic flares
  • symptom free between episodes
  • pain- very signficant
  • swelling erythema

QM:
* Bigtoe and the knee are most frequently affected
* Extra-articular attacks can sometimes occur, particularly affecting the olecranon bursae
* sudden, severe attacks of joint pain
* swelling,
* redness
* tenderness
Following acute attacks, symptoms resolve; however, joint damage can occur following recurrent attacks

6
Q

Common areas for gout to affect?

A
  • 1 MTP joint
  • Ankle
  • Wrist
  • Knee
7
Q

Inv for gout?

A
  • Uric acid- >360umol/L
    -< 360umol/L but strong suspicision of gout, repeat uric acid level after the flare has settled
  • Synovial fluid analysis- needle shaped negatively bifringent monosodium urate crystals under polarised light
  • Xray
  • PAINFUL, WARM SWOLLEN JOINT- need to rule out septic arthritis- basic obs, FBC, CRP, U&Es, LFTs, joint aspiration
8
Q

Radiologial features of gout?

A
  • joint effusion is an early sign
  • well-defined ‘punched-out’ erosions with sclerotic margins in a juxta-articular distribution, often with overhanging edges
  • relative preservation of joint space until late disease
  • eccentric erosions
  • no periarticular osteopenia (in contrast to rheumatoid arthritis)
  • soft tissue tophi may be seen
9
Q

Acute Management of gout?

A
  • NSAIDs or colchicine are first-line
    the maximum dose of NSAID should be prescribed until 1-2 days after the symptoms have settled gastroprotection (e.g. a proton pump inhibitor) may also be indicated
  • colchicine - has a slower onset of action
    may be used with caution in renal impairment: the BNF advises to reduce the dose if eGFR is 10-50 ml/min and to avoid if eGFR < 10 ml/min BNF
    the main side-effect is diarrhoea
  • oral steroids may be considered if NSAIDs and colchicine are contraindicated.
    a dose of prednisolone 15mg/day is usually used
  • another option is intra-articular steroid injection
  • if the patient is already taking allopurinol it should be continued
10
Q

When do you offer urate- loweing therapy?

A
  • British Society of Rheumatology Guidelines now advocate offering urate-lowering therapy to all patients after their first attack of gout
    ULT is particularly recommended if:
  • > = 2 attacks in 12 months
  • tophi
  • renal disease
  • uric acid renal stones
  • prophylaxis if on cytotoxics or diuretics
11
Q

What is the first- line therapy for urate-lowering therapy?

A
  • allopurinol is first-line
  • initial dose of 100 mg od, with the dose titrated every few weeks to aim for a serum uric acid of < 360 µmol/l
  • lower target uric acid level below 300 µmol/L may be considered for patients who have tophi, chronic gouty arthritis or continue to have ongoing frequent flares despite having a uric acid below 360 µmol/L
  • a lower initial dose of allopurinol should be given if the patient has a reduced eGFR
  • colchicine cover should be considered when starting allopurinol. NSAIDs can be used if colchicine cannot be tolerated. The BSR guidelines suggest this may need to be continued for 6 months
12
Q

What would you use if allopurinol is ineffective?

A
  • febuxostat (also a xanthine oxidase inhibitor)
13
Q

Lifestyle modifications for gout?

A
  • reduce alcohol intake and avoid during an acute attack
  • lose weight if obese
  • avoid food high in purines e.g. Liver, kidneys, seafood, oily fish (mackerel, sardines) and yeast products
14
Q

What is pseudogout caused by?

A
  • calcium pyrophosphate dihydrate cyrstals in the synovium
15
Q

What are the RF for pseudogout?

A
  • increasing age
  • in younger pts will have other RF:
    haemochromatosis
    hyperparathyroidism
    low magnesium, low phosphate
    acromegaly, Wilson’s disease
16
Q

Features of pseudogout?

A
  • knee, wrist and shoulders most commonly affected
  • joint aspiration: weakly-positively birefringent rhomboid-shaped crystals
  • x-ray: chondrocalcinosis
  • in the knee this can be seen as linear calcifications of the meniscus and articular cartilage
17
Q

Management of pseudogout?

A
  • aspiration of joint fluid, to exclude septic arthritis
  • NSAIDs or intra-articular, intra-muscular or oral steroids as for gout
18
Q
A

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