Crystal Arthropothy

Question 1

What is crystal arthropathy?

Answer 1

Deposition of mineralised material within joints and peri-articular tissue

Question 2

What type of crystals are found in gout?

Answer 2

Monosodium urate

Question 3

What type of crystals are found in pseudogout?

Answer 3

Calcium pyrophosphate dyhydrate

Question 4

What type of crystals are found in calcific periarthritis/tendonitis?

Answer 4

Basic calcium phosphate (hydroxy-apatite)

Question 5

What is a tophus?

Answer 5

A deposit of crystaline uric acid

Question 6

What causes tophi?

Answer 6

Massive accumulations of uric acid

Question 7

Where does the majority of urate come from in the body?

Answer 7

Purine degradation

Question 8

What is the most common cause of gout?

Answer 8

Reduced efficency of renal urate clearance

Question 9

What can cause overproduction of urate?

Answer 9

Malignancy
Lymphoproliferative, tumour lysis syndrome
Severe exfoliative psoriasis
Drugs - ethanol, cytotoxic drugs
Inborn errors of metabolism
HGPRT deficiency

Question 10

What can cause under excretion of urate?

Answer 10

Renal impairment
Hypertension
Hypothyroidism
Drugs - alcohol, low dose aspirin, diuretics, cyclosporin
Exercise, dehydration, starvation
Lead poisoning

Question 11

What is Lesch Nyan syndrome?

Answer 11

Deficiency of Hypoxanthine-Guanine Phosphoribosyl transferase (HGPRT) - X-linked recessive

Question 12

What are clinical features of Lesch Nyan syndrome?

Answer 12

Intellectual disability
Aggressive and impulsive behaviour
Self mutilation
Gout
Renal disease

Question 13

What is the most common demographic of gout?

Answer 13

Older men

Question 14

Why is gout less common in women?

Answer 14

Oestrogen leads to lower urate levels

Question 15

How is acute flare up of gout managed?

Answer 15

NSAIDS
Colchicine
Steroids

Question 16

How is uric acid lowered?

Answer 16

Xanthine oxidase inhibitor - allopurinol
Febuxostat
Uricosuric agents - sulphinpyrazone
Canakinumab

Question 17

What are rules for lowering uric acid?

Answer 17

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

Question 18

What cardiovascular and lifestyle factors need to be addressed in gout?

Answer 18

Hypertension
Smoking
High sugar diet
Alcohol
High fat diet
Obesity

Question 19

What population is most affected by pseudogout?

Answer 19

Elderly women

Question 20

What are the 3 main aetiologies for pseudogout?

Answer 20

Idiopathic
Familial
Metabolic

Question 21

What are triggers for flareups of pseudogout?

Answer 21

Trauma

Intercurrent illness

Question 22

How is pseudogout managed?

Answer 22

NSAIDs
Intraarticular steroids
No prophylactic therapies

Question 23

What is polymyalgia rheumatica?

Answer 23

Sudden onset of shoulder +/- pelvic girdle stiffness

Question 24

What are clinical features of polymyalgia rheumatica?

Answer 24

Anaemia, malaise, weight loss, fever, depression, arthralgia, synovitis

Question 25

How is polymyalgia rheumatica diagnosed?

Answer 25

Compatible history
Age>50
ESR>50
Dramatic steroid response
There is no specific diagnostic test

Question 26

What are differential diagnoses for polymyalgia rheumatica?

Answer 26

Myalgic onset inflammatory joint disease
Underlying malignancy
Inflammatory muscle disease
Hypo/hyperthyroidism
Bilateral shoulder capsulitis
Fibromyalgia

Question 27

How is polymyalgia rheumatica treated?

Answer 27

Prednisolone 15mg per day
18-24 month course
Bone prophylaxis