Crystal arthropathies and polymyalgia rheumatica

Question 1

what type of crystal deposition is found in gout?

Answer 1

monosodium urate

Question 2

what type of crystal deposition is found in pseudo gout?

Answer 2

calcium pyrophosphate dihydrate (CPPD)

Question 3

what is calcium phosphate hydroxyapatite found in?

Answer 3

calcific periarthritis/tendonitis

Question 4

what is the most common place of gout?

Answer 4

1st MTP joint in the toe

Question 5

where does uric acid come from and how do we get rid it?

Answer 5

purines which come from breakdown of DNA/RNA and from our diet
majority is excreted via the kidneys and a small proportion enters the biliary tract

Question 6

what is gout?

Answer 6

hyperuricaemia usually as a result of reduced renal excretion of uric acid
causes monosodium rate crystals to be deposited within joints

Question 7

what is the aetiology of gout?

Answer 7

either due to over production of under excretion of uric acid = hyperuricaemia

over production:

• malignancy i.e. lymphoproliferative, tumour lysis syndrome
• severe exfoliative psoriasis
• drugs i.e. ethanol, cytotoxic drugs (chemotherapy)

under excretion:

• renal impairement
• hypertension
• hypothyroidism
• drugs i.e. alcohol, aspirin, diuretics, cyclosporin
• exercise, starvation, dehydration
• lead poisoning

Question 8

what is the prevalence of gout in men compared to women?

Answer 8

gout more common in men 
oestrogen has a uricosuric effect making it very rare in younger women
men have higher levels of uric acid 
incidences of gout  
- increase with age in both sexes

Question 9

what is a typical history of a patient with gout?

Answer 9

acute attack of very painful, red, swollen 1st MTP joint of the toe
attack lasts about 7-10 days then eases off

Question 10

how would you investigate gout to rule out differentials?

Answer 10

needle aspiration
microscopy and culture (infection ?)
polarising microscopy (gout crytals)

check uric acid levels when attack has settled, not during attack

Question 11

what is the treatment for an acute flare of gout?

Answer 11

NSAIDS
colchicine (instead of NSAID)
intra articular steroids

Question 12

what treatment is given to lower uric acid levels in gout?

Answer 12

allopurinol

febuxostat

Question 13

when would you treat hyperuricaemia ?

Answer 13

don't treat after 1st attack unless:
- single attack of polyarticular gout
- trophaceous gout
- urate calculi
- renal insufficiency
treat if 2nd attack within 1yr

Question 14

what type of drug is allopurinol?

Answer 14

xanthine oxidase inhibitor

works to decrease uric acid levels

Question 15

what is pseudogout?

Answer 15

occurs in elderly females
mostly occurs in theknees
erratic flares

Question 16

what causes pseudo gout?

Answer 16

idiopathic
familial
metabolic
triggers: trauma, intercurrent illness

Question 17

in what condition is chonedrocalcinosis found in?

Answer 17

pseudo gout

Question 18

what is diagnostic of pseudo gout on microscopy?

Answer 18

pyrophosphate crystals

Question 19

what is the treatment for pseudo gout?

Answer 19

NSAIDS

intra articular steroids

Question 20

what is polymyalgia rheumatica?

Answer 20

inflammatory condition found in the elderly > 50yrs characterised by sudden onset of shoulder/pelvic girdle muscle stiffness and pain
close relationship to giant cell arteritis

Question 21

what are the symptoms of polymyalgia rheumatica?

Answer 21

sudden onset of shoulder +/- pelvis girdle muscle pain and stiffness 
malaise
anaemia
weight loss
fever
depression
arthralgia / synovitis occasionally

Question 22

what investigations would you carry out to diagnose polymyalgia rheumatica?

Answer 22

ESR (elevated > 45)
trial with steroid response
there is no specific diagnostic test

Question 23

what is the treatment for polymyalgia rheumatica?

Answer 23

steroids

+ bone prophylaxis with bisphosphonates

Question 24

what are the differential diagnoses of polymyalgia rheumatica?

Answer 24

myalgic onset inflammatory joint disease
underlying malignancy i.e. multiple myeloma, lung cancer
inflammatory muscle disease
hypo/hyperthyroidism
bilateral shoulder capsulitis
fibromyalgia

Question 25

name a syndrome that is associated with gout.

Answer 25

leach nyan syndrome

in born error of metabolism that results in a build up of uric acid in the body

• mental retardation
• self mutilation & aggressive/ impulsive behaviour
• gout
• renal disease

Question 26

name 2 differentials of gout.

Answer 26

chill blain
flare up of osteoarthritis
septic arthritis
pseudo gout

Question 27

what drug class is allopurinol?

Answer 27

xanthine oxidase inhibitor

Question 28

what feature on x-ray is suggestive of pseudo gout?

Answer 28

chondrocalcinosis

Question 29

what investigations would you carry out to diagnose pseudo gout?

Answer 29

joint aspiration for polarising microscopy

x-ray