Crystal Athropathies

Question 1

What is gout?

Answer 1

An inflammatory crystal arthropathy

Question 2

What causes gout?

Answer 2

Deposition of urate crystals within a joint

Question 3

Gout is usually as a result of what?

Answer 3

High serum uric acid levels

(hyperuricaemia)

Question 4

What is uric acid the final breakdown product of?

Answer 4

Purines

(formed in the DNA metabolism involving guanine and adenine)

Question 5

Hyperuricaemia me be caused, or exacerbated by which factors?

Answer 5

• Renal underexcretion (of uric acid)
• Diuretics
• Renal failure
• Excessive alcohol intake
• Diet (red meat, seafood)

Question 6

What is the enzyme within the breakdown pathway of purines which can be acted upon by urate lowering therapies?

Answer 6

Xanthine oxidase

(Coverts hypoxanthine to xanthine to uric acid)

Question 7

How is uric acid excreted from the body?

Answer 7

1. Renal (2/3rds)
2. GI (1/3rd)

Question 8

Uric acid crystal precipitation in joints can be triggered by what?

Answer 8

• Dehydration
• Trauma
• Surgery

Question 9

Which joints can be affected by gout?

Answer 9

Any joint

Most commonly the first MTP joint, ankle joint, knee joint

Question 10

When gout affects the MTP joint, what is the name of this specific condition?

Answer 10

Podagra

Question 11

How does gout present and what does it mimic?

Answer 11

1. Intensely painful
2. Red, hot and swollen

May mimic a septic arthritis

Question 12

What are gouty tophi?

Answer 12

Painless white accumulations of uric acid which can occur in soft tissues and occasionally erupt through the skin

Question 13

If untreated, how long will symtpoms of gout last before resolve?

Answer 13

7-10 days

Question 14

What can chronic gout result in?

Answer 14

Destructive erosive arthritis

Question 15

Describe the process by which a definitive diagnosis is made for gout

Answer 15

A sample of synovial fluid is acquired via joint aspirate

The fluid is examined with polarised microscopy and also with a gram stain (to rule out infective arthritis)

Uric acid crystals are needle shaped and display negative birefringence (yellow to blue) when lined aross the direction of polarisation

Question 16

What is the treatment for an acute gout attack?

Answer 16

1. NSAIDs
2. Corticosteroids
3. Opiod analgesics
4. Colchicine

Question 17

When would colchicine be administered to a patient for an acute gout attack?

Answer 17

When the patient cannot take NSAIDs

Question 18

What causes pseudogout?

Answer 18

Deposition of calcium pyrophosphate crystals within joints

Question 19

What is the term used to describe when calcium pyrophosphate deposition occurs in cartilage and other soft tissues in the absence of acute inflammation?

Answer 19

Chondrocalcinosis

Question 20

Where does pseudogout tend to affect?

Answer 20

1. Knee
2. Wrist
3. Ankle

Question 21

Which conditions does pseudogout commonly coexist with?

Answer 21

1. Hyperparathyroidism
2. Hypothyroidism
3. Renal osteodystrophy
4. Haemochromatosis
5. Wilson’s disease
6. Osteoarthritis

Question 22

Chronic calcium pyrophosphate deposition disease (CPPD) can result in which type of changes in joints?

Answer 22

Osteoarthritic

Question 23

What is the treatment for an acute attack of calcium pyrophosphate deposition disease?

Answer 23

1. NSAIDs
2. Corticosteroids (systemic and intra-articular)
3. Colchicine

Question 24

What is the prophylactic treatment for calcium pyrophosphate deposition disease?

Answer 24

There is no such treatment