crystal arthropathies

Question 1

what are crystal arthropathis

Answer 1

deposition of mineralised material within joints and peri-articular tissue

Question 2

what causes gout

Answer 2

monosodium urate

Question 3

what causes pseudogout

Answer 3

calcium pyrophosphate dehydrate (CPPD)

Question 4

where does our uric acid come from

Answer 4

2/3 from degradation of purines

1/3 dietary

Question 5

what happens to uric acid produced

Answer 5

majority excreted via kidney

remainder eliminated into biliary tract and converted by colonic bacterial uricase to allntoin

Question 6

in majority of people with gout, hyperuricaemia results from…

Answer 6

reduced efficiency of renal urate clearance

Question 7

overproduction causes of hyperuricemia

Answer 7

malignancy e.g. lymphoproliferative
severe exfoliative psoriasis
drugs e.g. ethanol, cytotoxic
HGPRT deficieny

Question 8

underexretion causes of hyperuricemia

Answer 8

renal impairment
hypertension 
hypothyroidism 
drugs e.g. low dose aspirin, cylosporin, diuretics
exercise, starvation, dehydration 
lead poisoning

Question 9

lesch Nyan syndrome

Answer 9

HGPRT deficiency
x-linked recessive

intellectual disability 
aggressive + impulsive behaviour 
self-mutilation 
gout 
renal disease

Question 10

what is HGPRT and why is deficiency bad

Answer 10

enzyme involved in recycling of purine bases

when deficient, cannot salvage proteins and they are broken down and excreted as uric acid
to compensate for loss of purine bases the body produces more purines which will cause more uric acdi

Question 11

pt Hx with gout

Answer 11

dehydration
alcohol 
overweight
classically occurs 1st MTP jiont foot 
pain 
typical episode 5-7days

Question 12

gout examination

Answer 12

erythema of skin
podigra is sevre
tophi (accumulation of uric acid)

Question 13

gout investigation

Answer 13

joint aspiration

Question 14

management of gout: acute flare

Answer 14

NSAIDs
colchicine
steroids (IA, IM, oral)

Question 15

management of gout: long term

Answer 15

if 2nd attack within 1yr

lower uric acid

Question 16

drugs for lowering uric acid

Answer 16

xanthine oxidase inhibitor e.g. allopurinol
febuxostat
uricosuric agents

Question 17

rules for lowering uric acid

Answer 17

• wait until acute attack has settles
• use prophylactic NSAIDs/low dose colchicine/steroids until urate level normal
• adjust allopurinol dose according to renal function

Question 18

pseudogout

Answer 18

knee

erratic flares

Question 19

pseudogout triggers

Answer 19

trauma

intercurrent illness

Question 20

management of pseudogout

Answer 20

IA steroids
analgesia
NSAIDs

(no prophylactic therapies)

Question 21

polymyalgia rheumatica

Answer 21

sudden onset of shoulder +/- pelvic girdle stiffness

Question 22

polymyalgia rheumatica cycle

Answer 22

PMR - giant cell arthritis - high ESR anaemia - PMR

Question 23

clinical features polymyalgia rheumatica

Answer 23

raised ESR
anaemia 
malaise
weight loss
fever 
depression 
occasional arthralgia/synovitis

Question 24

diagnosis of polymyalgia rheumatica

Answer 24

compatible Hx
age >50
ESR >50
dramatic steroid response

(no specific diagnostic test)

Question 25

treatment of polymyalgia rheumatica

Answer 25

prednisolone 15mg per day

bone prophylaxis

Question 26

gout crystals

Answer 26

shard shaped, negative bifringence

Question 27

pseudogout crystals

Answer 27

rhomboid, positive bifringence

Question 28

gout Rx

Answer 28

acute: NSAIDs, colchicine

long-term: allopurinol

Question 29

gout risks

Answer 29

men
DM, renal disease
alcohol 
drugs: thiazide, loop diuretics, low dose aspirin
HGRPT def