Crystal arthropathy

Question 1

What is crystal arthropathy?

Answer 1

group of joint disorders caused by deposits of crystals in joints and soft tissues around them

Question 2

What are the most common types of crystal arthropathy?

Answer 2

1. Gout

2. Calcium pyrophosphate deposition (CPPD) -Pseudo-gout

Question 3

What is acute CPPD?

Answer 3

acute monoarthropathy usually larger joints in elderly, usually spontaneous

Question 4

What is chronic CPPD?

Answer 4

inflammatory RA-like symmetrical polyarthritis and synovitis

Question 5

What are RF for CPPD?

Answer 5

1. Old age
2. Hyperparatyroidism
3. Haemochromtosis
4. Hypophosphatameia

Question 6

What does synovial fluid analysis show in CPPD?

Answer 6

weakly positively birefringent rhomboid-shaped crystals

Question 7

What would X ray show with CPPD?

Answer 7

and soft tissue calcium deposition on X ray

Question 8

How do you manage CPPD?

Answer 8

1. Mono/oligoarticular disease: Intra-articular corticosteroids +/- paracetamol
2. Polyarticular disease: NSAIDs or colchicine +/- paracetamol and systemic corticosteroids if 1st line fails/contraindicated
3. Chronic/recurrent: joint replacement

Question 9

What is normal epid for gout?

Answer 9

1. 3-6% men
2. 1-2% women
3. Rare in premenopausal women

Question 10

What are RF for gout?

Answer 10

1. Older age
2. Male sex
3. Use of drug e.g. aspirin, ciclosporin , tacrolimus or pyrazinmaide
4. Alcohol
5. Genetic
6. Chemo/cancer

Question 11

What are causes of gout?

Answer 11

1. Hyperuricaemia (either from reduced urate excretion or excess urate production)
2. Precipitated by trauma, infection.
3. Monosodium urate

Question 12

What are symptoms of GOUT?

Answer 12

1. Acute onset of severe joint pain
2. Swelling
3. Effusion
   Warmth
4. Eythema
5. Tenderness of involved joint
6. Tophi

Question 13

What joints are affected in gout?

Answer 13

Feet joint: first metatasophalangeal, tarsometatrsal and ankle joints

Question 14

How many joints are affected in gout?

Answer 14

Few affected joints usually monoarticular or <4 joints

Question 15

What are possible DDx for gout?

Answer 15

1. Pseudogout
2. Septic arthritis: EXCLUDE
3. Trauma
4. RA
5. Reactive arthritis
6. Psoriatic arthritis

Question 16

What investigation is used in gout?

Answer 16

arthrocentesis with synovial fluid analysis

Question 17

What would synovial fluid be like in Gout?

Answer 17

strongly negative birefringent needle-shaped crystals under polarised lights

Question 18

What is the 1st line management for acute gout?

Answer 18

1. NSAIDs e.g. naproxen 500mg twice daily 10-14 days
2. Corticosteroid e.g., prednisolone 20-40mg once daily
3. Colchicine 1.2mg

Question 19

What is 2nd line management of Gout?

Answer 19

IL-1 inhibitor e.g. anakinra

Question 20

What is management for recurrent gout?

Answer 20

• 1st line: allopurinol 100mg daily + NSAIDs
• 2nd line: febuxostat 40-80mg daily
• 3rd line: probenecid or sulfinpyrazone
• 4th line: pegloticase

Question 21

What are possible complications of gout?

Answer 21

1. Joint destruction
2. Kidney disease
3. Urolithiasis
4. Nephrolithiasis
5. Acute uric acid nephropathy

Question 22

What is gout a RF for?

Answer 22

mortality from cardiovascular and renal disease

Question 23

What are symptoms of pseudogout?

Answer 23

1. Acute monoarthritis
2. Large joints – knee
3. Polyarticular (chronic)

Question 24

What is pseudogout caused by?

Answer 24

1. Precipitated by trauma, illness.
2. Calcium pyrophosphate.
3. Idiopathic
4. hyperPTH, hypoPO4, hypoMg, metabolic

Question 25

What are additional XR changes in psuedogout?

Answer 25

1. Linear, stippled radio-opaque deposits in fibro cartilage OR hyaline cartilage 2. Calcified tendons 3. Subchondral cysts

Question 26

What other investigations can be used in psudeogout?

Answer 26

1. Serum calcium --> normal or elevated | 2. Serum parathyroid hormone --> normal or elevated

Question 27

What can lead to hyperuricaemia in gout?

Answer 27

1. Increased intake of uric acid in gout often due to high purine diet, alcohol 2. Increased production can be malignancy-related (tumour lysis syndrome) 3. Decreased excretion is usually the result of diuretic medication

Question 28

What would aspirate show in gout?

Answer 28

1. turbid, yellow, low viscosity fluid. Raised WCC (neutrophils) 2. Needle shaped, -vely birefringent crystals

Question 29

What would bloods show in gout?

Answer 29

1. elevated WCC 2. CRP 3. uric acid (4-6 weeks later)

Question 30

What would XR show in gout?

Answer 30

“rat bite” erosions

Question 31

What do you give for acute attack of gout?

Answer 31

1. NSAIDs +/- PPI 2. Colchicine (anti-mitotic) 3. Corticosteroids

Question 32

What do you give for prophylaxis in gout?

Answer 32

1. Allopurinol 2. febuxostat 3. probenecid

Question 33

How does colchine MOA work?

Answer 33

- Binds to tubulins & prevents assembly of microtubules --> no WBC migration --> less inflammation - Idea of prevention in gout is to minimise uric acid levels (so adjusting diet, alcohol etc. is also recommended).