crystal arthropathies

Question 1

what are crystal arthropathies?

Answer 1

a diverse group of disorcers characterised by the deposition of various minerals in joints and soft tissues, leading to inflammation

Question 2

what crystals are deposeted in gout?

Answer 2

monosodium urate crystals

Question 3

what crystals are deposited in pseudogout?

Answer 3

calcium pyrophosphate crystal

Question 4

what crystals are deposited in hydroxyapatite?

Answer 4

basic calcium phosphate deposition

Question 5

who is increased risk of getting gout?

Answer 5

-men

Question 6

what causes gout?

Answer 6

hyperuricaemia

Question 7

what increases urate production?

Answer 7

• inherited enzyme defects
• high dietary purine intake (red meat, seafood, corn syrup)
• high alcohol intake (beer, spirits)
• psoriasis
• haemolytic disorders
• myeloproliferative/ lymphoproliferative disorders

Question 8

what reduces urate excretion? (causing gout)

Answer 8

• chronic renal impairement
• volume depletion (heart failure)
• hypothyroidism
• diuretics

Question 9

most commonly affected joint in acute gout?

Answer 9

1st MTP joint in foot

Question 10

how long does it take for acute gout take to stop being painful?

Answer 10

3 days with treatment

10 days without

Question 11

what are the uric acid levels like in acute gout?

Answer 11

can be normal

Question 12

investigations for chronic gout?

Answer 12

• history
• serum uric acid raised (25-50% normal in acute episodes)
• raised inflammatory markers
• aspiration and polarised microscopy of synovial fluid
• X rays

Question 13

what joints does gout affect?

Answer 13

• 1st MTP joint (most commonly)
• ankles
• knees
• elbows
• wrists
• fingers

Question 14

what increases risk of getting gout?

Answer 14

• male
• family history of gout
• alcohol
• diet high in purine (meat + seafood)
• CVD/ kidney disease
• hypothyroidism
• diuretics
• obesity

Question 15

how does gout typically present?

Answer 15

• sudden onset of pain
• redness
• joint swelling
• limited movement
• lingering discomfort

Question 16

how is gout diagnosed?

Answer 16

• 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

Question 17

how may gout appear on an Xray?

Answer 17

• the joint space will be maintained
• lytic lesions
• punched out erosions that may have sclerotic borders or overhanging lesions

Question 18

how is gout managed?

Answer 18

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)

Question 19

when would colchicine be given during an acute attack of gout?

Answer 19

• 2nd line to NSAIDs
• if NSAIDs aren’t working
• if patient has renal impairment or CVD

Question 20

what are side effects of colchicine?

Answer 20

GI SE:

-dose dependant diarrhoea so if the patient is experiencing diarrhoea try to lower the dosage and diarrhoea may stop

Question 21

should allopurinol be given during an acute attack of gout?

Answer 21

• 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

Question 22

what are MOA of allopurinol?

Answer 22

-its a xanthate oxidase inhibitor so lowers uric acid levels

Question 23

what is Pseudogout?

Answer 23

-a type of crystal arthropathy that usually affects the knee, hips, shoulder and wrists causes by a build up of calcium pyrophosphate crystals

Question 24

what increases chances of getting Pseudogout?

Answer 24

• increase in age
• family history of pseudogout
• mineral imbalances (raised calcium or iron levels, decreased magnesium levels)
• joint trauma

Question 25

how does Pseudogout present?

Answer 25

• joint pain
• swollen joint
• redness in joint

typically occurs in knee, hips, shoulder and wrists

Question 26

how is Pseudogout diagnosed?

Answer 26

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

Question 27

what is the management of Pseudogout?

Answer 27

• NSAIDs (naproxen or ibuprofen)
• colchicine (if renal impairment or CVD)
• oral/injetion steroids
• joint aspiration

in severe cases= arthrocentesis (joint washout)

Question 28

what are some complications of Pseudogout?

Answer 28

joint damage with similar signs or OA or RA