crystal arthropathies

Question 1

2 main conditions

Answer 1

gout and psuedogout

Question 2

gout is deposition of

Answer 2

monosodium urate

Question 3

psuedogout is deposition of

Answer 3

calcium pyrophosphate deposition disease (CPPD)

Question 4

definition of gout

Answer 4

type of inflammatory arthritis which is caused by the deposition of rate crystal in joints due to high serum uric acid levels (hyperuricaemia)

Question 5

gout in men

Answer 5

is the most common type of inflammatory arthritis

Question 6

what is uric acid

Answer 6

uric acid is the final product in the breakdown of purines in DNA metabolism

Question 7

uric acid pathway

Answer 7

ADENOSINE> HYPOXATNHINE> XANTHINE> URIC ACID which is exerted by kidneys and GI tract or converted to allantoin

Question 8

what converts hypoxanthine to xanthine

Answer 8

xanthine oxidase (ALLOPURINOL IS A XANTHINE OXIDASE INHIBITOR)

Question 9

causes of hyperuricaemia

Answer 9

1. decreased renal clearance due to renal failure, dehydration, thiazide diuretics (bendroflumethiazide)
2. increased purines in the diet (anchovies, shell fish, red meat)
3. any condition which increases cell turnover (psoriasis, sepsis, chemotherapy)

Question 10

definition of hyperuricaemia

Answer 10

serum uric acid level greater than 7mg/dl (serum urate greater than 360)

Question 11

what can the diagnosis of gout not be based upon alone

Answer 11

hyperuricaemia as many people do have hyperuricaema but do not develop gout

Question 12

diagnosis of gout

Answer 12

joint aspirate and examination of aspirate using polarised light microscopy

Question 13

what crystals are seen in gout

Answer 13

negatively birefringement needle shaped crystals

Question 14

when might serum urate actually surprisingly be normal

Answer 14

in 25% of acute attacks of gout it will be normal because the rate is sequestered in the joint

Question 15

when is the best time to measure serum urate

Answer 15

2 weeks after acute attack

Question 16

presentation of gout

Answer 16

• red, hot swollen joint

- excruciating pain which often comes on over night

Question 17

what is the most common joint affected in gout

Answer 17

1st metatarsophalyngeal joint where it is called PODAGRA

Question 18

chronic gout can cause

Answer 18

tophi, renal stones and and an interstitial nephritis

Question 19

tophi

Answer 19

deposit of uric acid crystals in long standing gout which is white and painless but destroys and erodes the joint

Question 20

investigations

Answer 20

• joint aspirate
• serum urate
• raised inflammatory markers: ESR, CRP and PV
• x-ray: normal in acute attacks but in chronic gout shows erosion and joint destruction

Question 21

management of acute attack of gout

Answer 21

• NSAIDS and co-codamol/ tramadol and ice

Question 22

if NSAIDS are contra-indicated what do you use

Answer 22

Colchicine (too much colchicine gives you diarrhoea)

Question 23

when might NSAIDS and colchicine be contra-indicated and if so what should you use instead

Answer 23

renal impairment so use intra-articular steroids

Question 24

preventing gout

Answer 24

if someone has had 2 attacks within 6 months give allopurinol

Question 25

what is so so so important to remember about allopurinol

Answer 25

NEVER EVER GIVE IT IN AN ACUTE ATTACK, CAN ONLY BE GIVEN 2 WEEKS AFTER ACUTE ATTACK

Question 26

if allopurinol is contra-indicated

Answer 26

febuxostat

Question 27

psuedogout caused by deposition of

Answer 27

calcium pyrophosphate crystals

Question 28

who is psuedogout more common in

Answer 28

elderly

Question 29

where does psuedogout affect

Answer 29

fibrocartilage of knees, wrists and ankles

Question 30

what is chonedrocalcinosis

Answer 30

deposition of calcium pyrophosphate crystals in cartilage in the absence of acute inflammation it comes under the umbrella of CPPD

Question 31

diagnosis of psuedogout

Answer 31

joint aspirate and examination under polarised light microscopy

Question 32

what crystals are seen in psuedogout

Answer 32

positively birefringement rhomboid shaped crystals

Question 33

what is psuedogout associated with

Answer 33

• hyperparathyroidism, hypothyroidism, raging, haemachromatosis

Question 34

treatment of psuedogout

Answer 34

NSAIDS or colchicine if nsaids contra-indicated, if renal impairment then intra-articular steroids