Crystal Arthropathies

Question 1

what are crystal arthropathies characterised by?

Answer 1

deposition of mineralised material within joints and peri-articular tissue

Question 2

name common crystal arthropathies and their crystals

Answer 2

monosodium urate - gout
calcium pyrophosphate dihydrate - pseudogout
basic calcium phosphate hydroxy-apatite - calcific periarthritis/tendonitis

Question 3

what is a TOPHUS/TOPHI

Answer 3

massive accumulations of uric acid

Question 4

with a diagram describe purine metabolism

Answer 4

see notes

Question 5

causes of hyperuricaemia: overproduction

Answer 5

malignancy e.g. lymphoproliferative, tumour lysis syndrome
severe exfoliative psoriasis
drugs e.g. ethanol, cytotoxic drugs
inborn errors of metabolism
HGRPT deficiency

Question 6

causes of hyperuricaemia: under excretion

Answer 6

renal impairment
hypertension
hypothyroidism
drugs e.g. alcohol, low dose aspirin, diuretics, cyclosporin
exercise, starvation, dehtdration
lead poisoning

Question 7

describe Lesch Nyan syndrome

Answer 7

HGPRT deficiency
X-linked recessive
intellectual disability
aggressive and impulsive behaviour
self mutilation
gout
renal disease

Question 8

management of gout: acute flare

Answer 8

NSAIDs
colchicine
steroids IA, IM, oral

Question 9

management of gout: hyperuricaemia

Answer 9

does it need to be treated?
1st attack not treated unless: single attack of polyarticular gout, tophaceous gout, urate calculi, renal insufficiency
treat 2nd attack if within 1 yr
prophylactically prior to treating certain malignancies
do not treat if asymptomatic

Question 10

how can you lower uric acid?

Answer 10

• Xanthine oxidase inhibitor e.g. Allopurinol
• Febuxostat
• Uricosuric agents e.g. sulphinpyrazone, probenecid, benzbromarone
• Canakinumab

Question 11

what are the rules for loweringuric acid levels?

Answer 11

Wait until the acute attack has settled before attempting to reduce the urate level
Use prophylactic NSAIDs or low dose colchicine/steroids until urate level normal
Adjust allopurinol dose according to renal function

Question 12

who gets pseudogout?

Answer 12

elderly females

Question 13

cauases of pseudogout

Answer 13

idiopathic
familial
metabolic

Question 14

triggers of pseudogout

Answer 14

trauma

intercurrent illness

Question 15

management of pseudogout

Answer 15

NSAIDs
IA steroids
no prophylactic therapies

Question 16

cycle of polymyalgia rheumatica

Answer 16

polymyalgia rheumatica –> giant cell arteritis –> high ESR anaemia
20% with PMR have GCA
50% with GCA have PMR

Question 17

what is polymyalgia rheumatica

Answer 17

sudden onset of shoulder +/- pelvic girdle stiffness

Question 18

polymyalgia rheumatica age

Answer 18

Rare <50

usuaally > 70

Question 19

polymyalgia rheumatica M:F

Answer 19

1:2

Question 20

polymyalgia rheumatica ESR

Answer 20

usually > 45 often 100

Question 21

polymyalgia rheumatica symptoms

Answer 21

malaise
weight loss
fever
depression
arthralgia
synovitis

Question 22

polymyalgia rheumatica diaagnosis

Answer 22

compatible Hx
Age >50
ESR >50
dramatic steroid response
no specific diagnostic test

Question 23

polymyalgia rheumatica DDx

Answer 23

• Myalgic onset Inflammatory joint disease
• Underlying malignancy
– e.g Multiple myeloma, lung cancer
• Inflammatory muscle disease
• Hypo/ hyperthyroidism
• Bilateral shoulder capsulitis
• Fibromyalgia

Question 24

treatment of polymyalgia rheumatica

Answer 24

prednisolone 15mg daily initially
18-24 month course
bone prophylaxis