Crystal Arthritis

Question 1

what is gout?

Answer 1

inflammation in the joint triggered by uric acid crystals

Question 2

who more commonly gets gout, F or M?

Answer 2

M

rate of gout for F starts to increase after menopause

Question 3

what causes uric acid crystal deposition?

Answer 3

hyperuricaemia

encouraged by low temperature of synovial fluid

Question 4

what are the 3 main reasons for hyperuricaemia?

Answer 4

excess consumption
over production
under excretion

Question 5

why can psoriasis cause hyperuricaemia?

Answer 5

causes increased urate production

Question 6

why can chronic renal impairment cause hyperuricaemia?

Answer 6

causes reduced urate excretion

Question 7

why can a high alcohol intake cause hyperuricamia?

Answer 7

causes increased urate production

Question 8

why can a high red meat or seafood intake cause hyperuricaemia?

Answer 8

causes increased urate production

Question 9

why do diuretics cause hyperthyroidisim?

Answer 9

cause reduced urate production

Question 10

in acute gout, usually only one joint is involved, which are the most likely joints?

Answer 10

1. first metatarsalpharyngel (MTP)
2. ankle
3. knee

Question 11

compare rates of acute gout settling- treatment or no treatment?

Answer 11

no treatment- 10 days

treatment- 3 days

Question 12

compare the serum urate levels of acute to gout to chronic gout?

Answer 12

acute gout- urate levels may be normal

chronic gout- urate levels are high

Question 13

compare acute gout to chronic gout in terms of the number of joints involved

Answer 13

acute- only one joint involved

chronic- multiple joints

Question 14

why can chronic gout cause renal impairement?

Answer 14

uric acid crystallisation can occur in the glomeruli and damage the kidneys

Question 15

what is the gold standard way to diagnose gout?

Answer 15

polarising microscopy of synovial fluid

Question 16

what are the 3 main medications used in the treatment of acute gout?

Answer 16

NSAIDs
Colchicine
Steroids

Question 17

what treatments are used in the prophylaxis of recurring gout?

Answer 17

allopurinol
febuxostat
uricosurics
(2-4 weeks after acute attack)
initiially treat acute attack with NSAID, colchine or steroids

Question 18

what crystals are deposited in joints in pseudogout?

Answer 18

calcium pyrophosphate

Question 19

compare the shape of calcium pyrophosphate crystals to uric acid crystals?

Answer 19

calcium pyrophosphae- blunt

uric acid crystals- long and sharp

Question 20

what is the treatment of acute pseudogout?

Answer 20

NSAIDs
Colchicine
Steroids
Rehydration

Question 21

what is the treatment of chronic pseudogout?

Answer 21

no long term treatment, treat acute episodes

Question 22

what is milwaukee shoulder?

Answer 22

destructive shoulder arthropathy due to hydroxyapatite crystal deposition in/around joint

Question 23

what is the treatment of hydroxyapatite crystal deposition?

Answer 23

NSAIDs
intra-articula steroid injecionts
physiotherapy (to mobilise joint)
partial or total arthroplasty

Question 24

what nucleotides are broken down to form uric acid?

Answer 24

purines (adenine and guanine)

Question 25

what is the name of gout affecting the first metatarsalphalangeal (MTP) joint?

Answer 25

podagra

Question 26

how does gout present?

Answer 26

intensely painful, red, hot swollen joint

Question 27

what diagnosis looks similar to gout but is much more serious?

Answer 27

septic arthritis

Question 28

what are gout tophi?

Answer 28

painless white accumulations of uric acid which occasionally erupt through the skin near a joint

Question 29

what do uric acid crystals display under polarised microscopy?

Answer 29

negative birefringence

Question 30

what is chondrocalcinosis?

Answer 30

calcium pyrophosphate deposition in cartilage and other soft tissues (no acute inflammation)

Question 31

what are the 2 conditions that can occur in calcium pyrophosphate deposition disease?

Answer 31

pseudogout | chondrocalcinosis

Question 32

what enzyme do allopurinol and febuxostat work on? and what is the mechanism?

Answer 32

xanthine oxidase | they are xanthine oxidase inhibitors so prevent xanthine being converted to uric acid

Question 33

why should patients on azathioprine not be prescribed allopurinol?

Answer 33

interaction causing irreversible bone marrow failure

Question 34

what should you do when giving allopurinol to a patient with renal impairment?

Answer 34

lower dose of allopurinol

Question 35

when is febuxostat used over allopurinol in the prophylaxis of gout?

Answer 35

in those who cannot tolerate allopurinol

Question 36

what patients should febuxostat be used in caution?

Answer 36

patients with ischaemic heart disease