Lecture 18 Crystal Arthropathy

Question 1

Name 3 common crystal deposition disease

Answer 1

o Monosodium urate - gout
o Calcium pyrophosphate dihydrate (CPPD) - Pseudogout
o Basic calcium phosphate hydroxy-apatite (BCP) – calcific periarthritis/tendonitis

Question 2

In terms of Hyperuricaemia what causes overproduction

Answer 2

Malignancy, severe exfoliative psoriasis, drugs (ethanol, cytotoxic drugs), Inborn errors of metabolism, HGPRT deficiency

Question 3

In terms of Hyperuricaemia what causes under excretion

Answer 3

Renal impairment, hypertension, hypothyroidism, Drugs (alcohol, low dose aspirin, diuretics, cyclosporin), exercise, starvation, dehydration, lead poisoning

Question 4

What is Lesch Nyan Syndrome

Answer 4

HGPRT deficiency

Question 5

What is HGPRT

Answer 5

An enzyme that plays a key role in recycling of the purine bases, hypoxanthine and guanine into the purine nucleotide pools.

In absence of HPRT, these purines are degraded and excreted as uric acid

Question 6

What are the clinical features of Lesch Nyan Syndrome

Answer 6

Gout, renal disease, intellectual disability, X-linked recessive, self-mutation, aggressive and impulsive behaviour

Question 7

How is gout managed in an acute flare

Answer 7

NSAIDs, Colchine, Steroids (I/A, I/M, oral)

Question 8

Name drugs used to lower Uric Acid

Answer 8

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

Question 9

What is the aetiology of Pseudogout

Answer 9

Idiopathic, familial, metabolic

Question 10

What are the triggers for Pseudogout

Answer 10

Trauma, intercurrent illness

Question 11

What is the difference between Gout and Pseudogout

Answer 11

While gout is caused by uric acid crystals; pseudogout is caused by calcium pyrophosphate dehydrate crystals (CPPD)

Question 12

What is the management of Pseudogout

Answer 12

NSAIDs, I/A steroids

Question 13

What is Polymyalgia Rheumatica

Answer 13

Inflammatory disorder that causes muscle pain and stiffness

Question 14

How is Polymyalgia Rheumatica diagnosed

Answer 14

Compatible history
Age>50
ESR>50
Dramatic steroid response
No specific

Question 15

What are the differential diagnosis Polymyalgia Rheumatica

Answer 15

Underlying malignancy, inflammatory muscle disease, hypo/hyperthyroidism, fibromyalgia, bilateral shoulder capsulitis

Question 16

How is Polymyalgia Rheumatica treated

Answer 16

Prednisolone

Bone prophylaxis- Bisphosphonates