crystal arthropathies Flashcards
what are crystal arthropathies?
a diverse group of disorcers characterised by the deposition of various minerals in joints and soft tissues, leading to inflammation
what crystals are deposeted in gout?
monosodium urate crystals
what crystals are deposited in pseudogout?
calcium pyrophosphate crystal
what crystals are deposited in hydroxyapatite?
basic calcium phosphate deposition
who is increased risk of getting gout?
-men
what causes gout?
hyperuricaemia
what increases urate production?
- inherited enzyme defects
- high dietary purine intake (red meat, seafood, corn syrup)
- high alcohol intake (beer, spirits)
- psoriasis
- haemolytic disorders
- myeloproliferative/ lymphoproliferative disorders
what reduces urate excretion? (causing gout)
- chronic renal impairement
- volume depletion (heart failure)
- hypothyroidism
- diuretics
most commonly affected joint in acute gout?
1st MTP joint in foot
how long does it take for acute gout take to stop being painful?
3 days with treatment
10 days without
what are the uric acid levels like in acute gout?
can be normal
investigations for chronic gout?
- history
- serum uric acid raised (25-50% normal in acute episodes)
- raised inflammatory markers
- aspiration and polarised microscopy of synovial fluid
- X rays
what joints does gout affect?
- 1st MTP joint (most commonly)
- ankles
- knees
- elbows
- wrists
- fingers
what increases risk of getting gout?
- male
- family history of gout
- alcohol
- diet high in purine (meat + seafood)
- CVD/ kidney disease
- hypothyroidism
- diuretics
- obesity
how does gout typically present?
- sudden onset of pain
- redness
- joint swelling
- limited movement
- lingering discomfort
how is gout diagnosed?
- usually a clinical diagnoses
- raised uric acid levels (bloods or urine)
Aspiration to rule out septic arthritis!!:
- in septic arthritis there will be bacteria found in aspiration whereas no bacteria will be found in gout
- monosodium urate crystals are found in gout aspiration
- if gout crystals are looked at underneath polarised light they will appear as needle like crystals with a negative birefringement
how may gout appear on an Xray?
- the joint space will be maintained
- lytic lesions
- punched out erosions that may have sclerotic borders or overhanging lesions
how is gout managed?
ACUTE FLARE:
1st= NSAIDs (naproxen or ibuprofen)
2nd= Colchicine (use if patient has renal impairment of CVD) SE: dose dependant diarrhoea so try lowering dose if patient experiencing diarrhoea
3rd= steroids
PROPHYLAXIS:
- allopurine (works as a xanthate oxidase inhibitor to lower uric acid levels)
- lifestyle changes (lose weight, decrease purine intake, decrease alcohol intake and stay hydrated)
when would colchicine be given during an acute attack of gout?
- 2nd line to NSAIDs
- if NSAIDs aren’t working
- if patient has renal impairment or CVD
what are side effects of colchicine?
GI SE:
-dose dependant diarrhoea so if the patient is experiencing diarrhoea try to lower the dosage and diarrhoea may stop
should allopurinol be given during an acute attack of gout?
- allopurinol should NOT BE STARTED during an acute attack
- wait for acute attack to end and then allopurinol may be started, once started it can be continued to be taken throughout next acute attack
what are MOA of allopurinol?
-its a xanthate oxidase inhibitor so lowers uric acid levels
what is Pseudogout?
-a type of crystal arthropathy that usually affects the knee, hips, shoulder and wrists causes by a build up of calcium pyrophosphate crystals
what increases chances of getting Pseudogout?
- increase in age
- family history of pseudogout
- mineral imbalances (raised calcium or iron levels, decreased magnesium levels)
- joint trauma
how does Pseudogout present?
- joint pain
- swollen joint
- redness in joint
typically occurs in knee, hips, shoulder and wrists
how is Pseudogout diagnosed?
need to exclude septic arthritis!!!
Aspiration:
- in septic arthritis you will find bacteria whereas no bacteria is found in Pseudogout
- calcium phosphate crystals
- rhomboid shaped crystals
- positive birefringement under polarised light
Xray: -chondrocalcinosis is diagnostic (this is when there is a white line between the joints caused by a build up of calcium) -LOSS similar to OA Loss of joint space Osteophytes Sclerosing Subchondral cysts
what is the management of Pseudogout?
- NSAIDs (naproxen or ibuprofen)
- colchicine (if renal impairment or CVD)
- oral/injetion steroids
- joint aspiration
in severe cases= arthrocentesis (joint washout)
what are some complications of Pseudogout?
joint damage with similar signs or OA or RA
