Crystal Arthropathies

Question 1

what is gout

Answer 1

inflammation in the joint triggered by uric acid crystals

Question 2

what is the value that indicates hyperuricemia in gout

Answer 2

>0.42mmol/l

Question 3

what is the prevalence of gout

Answer 3

1.4 in UK, 3.9 in US 7% in men over 65 and 3% in women over 85 male > female

Question 4

what is affected during acute gout

Answer 4

monoarthropathy = 1st MTP > ankle > knee usually an abrupt onset over night

Question 5

how long does acute gout take to settle

Answer 5

10 days without treatment 3 days with treatment

Question 6

what is uric acid levels during attack of gout

Answer 6

it may be normal

Question 7

what is chronic gout usually associated with

Answer 7

diuretics

Question 8

what is uric acid levels in chronic gout

Answer 8

high it is the deposit of uric crystals in people with long standing hyperuricaemia

Question 9

what happens during chronic gout

Answer 9

they may get acute attacks

Question 10

what is the cause of gout

Answer 10

either increased urate production or reduced urate excretion

Question 11

what is the more common cause of gout

Answer 11

reduced urate excretion

Question 12

what causes increased urate production

Answer 12

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

Question 13

what causes reduced urate excretion

Answer 13

chronic renal impairment volume depletion eg heart failure hypothyroidism diuretics cytotoxics eg cyclosporine

Question 14

how is gout diagnosed

Answer 14

raised inflammatory markers serum uric acid raised synovial fluid biopsy renal impairment (may be cause or effect) Xrays

Question 15

what is seen in synovial fluid biopsy in gout

Answer 15

polarising microscopy shows needle shaped negatively befringement crystals

Question 16

how is acute attack of gout treated

Answer 16

NSAIDs colchicine IA steroids (often in people unable to take above)

Question 17

what is colchicine and how does it work

Answer 17

decreases swelling and lessening the build up of uric acid crystals that cause pain in the affected joint

Question 18

what is given prophylactically in gout

Answer 18

allopurinol febexostat start 2-4 weeks after acute attack require cover with NSAIDs etc

Question 19

what is allopruinol

Answer 19

purine analog; it is a structural isomer of hypoxanthine (a naturally occurring purine in the body) and is an inhibitor of the enzyme xanthine oxidase therefore, decreases uric acid formation

Question 20

what is febexostat

Answer 20

also inhibits xanthine oxidase and therefore reduces uric acid formation

Question 21

what is difference between pseudogout and gout

Answer 21

both are caused by large crystal deposits in joint but it is different crystals

Question 22

who is pseudogout common in

Answer 22

elderly

Question 23

what does pseudogout effect

Answer 23

fibrocartilage - knees, wrist, ankles

Question 24

what are the two types of crystals in pseudogout

Answer 24

calcium pyrophosphate crystals calcium hydroxyapatite crystals

Question 25

what are the associated conditions in pseudogout

Answer 25

hyperparathyroidism familial hypocalciuric hypercalcaemia haemochromatosis haemosiderosis hypophosphatasia hypomagnesia hypothyroidism gout neuropathic joints ageing amyloidosis trauma

Question 26

how is pseudogout diagnosed

Answer 26

histology of calcium pyrophosphate crystals and marked rise in inflammatory markers

Question 27

what does calcium pyrophosphate crystals in pseudogout look like histologically

Answer 27

envelope shaped mildly positive birefringent (refractive index)

Question 28

how is pseudogout treated

Answer 28

NSAIDs Colchicine Steroids Rehydration

Question 29

what is hydroxyapatite

Answer 29

hydroxyapatite crystal deposition in or around the joint

Question 30

what does this crystal deposition in hydroxyapatite lead to

Answer 30

release of collagenases, serine proteinases and IL-1 acute and rapid deterioration

Question 31

who does hydroxyapatite affect

Answer 31

females, 50-60 years

Question 32

what is symptom of hydroxyapatite

Answer 32

Milwaukee shoulder

Question 33

what does this symptom of hydroxyapatite entail

Answer 33

limited range of motion joint pain and inflammation synovial haemorrhagic effusion

Question 34

how is hydroxyapatite treated

Answer 34

NSAIDs IA steroid injection physiotherapy partial or total arthroplasty