Crystal Arthropathies and Polymyalgia Rheumatica (PMR)

Question 1

What are crystal deposition diseases characterised by?

Answer 1

Deposition of mineralised material within joints and peri-articular tissue

Question 2

Which crystal deposition diseases are commonly seen in practice?

Answer 2

Gout
Pseudogout
Calcific periarthritis/tendonitis

Question 3

Which crystal is deposited in gout?

Answer 3

Monosodium urate

Question 4

Which crystal is deposited in pseudogout?

Answer 4

Calcium pyrophosphate dihydrate (CPPD)

Question 5

Which crystal is deposited in calcific periarthirits/tendonitis?

Answer 5

Basic calcium phosphate hydoxy-apatite (BCP)

Question 6

In gout, what is there excess of in the blood?

Answer 6

High levels or purines/uric acid

->uric acid is the end product of metabolised purines

Question 7

How does the body get purines?

Answer 7

Through the diet

Question 8

Hyperuricaemia?

Answer 8

Overproduction of uric acid in the blood

Question 9

In which conditions is hyperuricaemia commonly seen?

Answer 9

Lymph proliferative malignancies
Tumour lysis syndrome
Severe exfoliative psoriasis
Renal impairment

Question 10

Which drugs can cause hyperuricaemia?

Answer 10

Ethanol (alcohol)
Cytotoxic drugs

Question 11

Where are purines excreted from?

Answer 11

Approx 75% from kidneys
25% from GIT

Question 12

What is a major source of purines?

Answer 12

Alcohol

Question 13

Lesch Nyan Syndrome?

Answer 13

HGPRT deficiency (type of enzyme) so uric acid overproduction
Intellectual disability with aggressive and impulsive behaviour

Question 14

What kind of inherited condition is Lesch Nyan syndrome?

Answer 14

X-linked recessive

Question 15

Which other health issues can occur with Lesch Nyan syndrome?

Answer 15

Self mutilation (self harm)
Gout
Renal disease

Question 16

Who more commonly gets gout?

Answer 16

Older men

->think of GP case I saw cos that was an old man
also note, very rare in premenopausal women so if see this in diagnosis, look again and make sure

Question 17

Is there a link to family history in gout?

Answer 17

Yes, v strong FH association

Question 18

Signs of gout?

Answer 18

Red and swollen joint

->look for scalp psoriasis as well, as previously mentioned, can be caused by psoriasis

Question 19

Risk factors for gout?

Answer 19

Hypertension
Diabetes
Hyperlipidaemia
Family history

->often lifestyle driven by a lifestyle of excess e.g. excess eating and drinking but can be caused by medications too

Question 20

Some of the differential diagnosis or gout?

Answer 20

Any inflammatory joint condition
Infection- e.g. if swollen knee, aspirate to rule out infection

Question 21

What is the gold-standard investigation for gout?

Answer 21

Fluid sample from joint to look under microscope

Question 22

Would you test urate in bloods in someone with suspected gout?

Answer 22

Can be difficult as if acute attack of gout, urate levels will be low

->if cannot identify gout from a joint aspirate, check urate blood levels again in a few weeks

Question 23

What are x-rays good for regarding joints?

Answer 23

To see if there is any damage to joint but not useful in an acute attack

Question 24

Basically- are x-rays and US good for gout?

Answer 24

Not really as would need to be really advanced before seeing anything so by that point, will have been missed

Question 25

Which joint does gout classically start?

Answer 25

First MCP joint

Question 26

Does gout start suddenly or build up?

Answer 26

Starts very suddenly

Question 27

Tophi build up in gout. What are they?

Answer 27

Deposit of the monsodium urate crystals ->very painful

Question 28

Tophus tophi?

Answer 28

Massive accumulations of uric acid ->check pinna of ear as can accumulate here too

Question 29

How many joints tend to be affected by gout?

Answer 29

Typically one but can occur in more than one

Question 30

Gold standard management of gout?

Answer 30

Aspirate the joint and then inject steroids

Question 31

What is used in the management of an acute flair of gout?

Answer 31

NSAIDs Colchicine Steroids

Question 32

Sometimes gout doesn't need to be treated. The first attack of gout is only treated if....

Answer 32

1. Single attack of polyarticular gout 2. Tophaceous gout 3. Urate calculi 4. Renal insufficiency

Question 33

Who cannot have anti-inflammatory durgs?

Answer 33

Patients with renal insufficiency

Question 34

What is the first line of treatment for lowering uric acid?

Answer 34

Xanthine oxidase inhibitors e.g. Allopurinol ->can be used in renal impairment too If not tolerated, Febuxostat is next line of action

Question 35

What are the rules to follow when lowering uric acid levels?

Answer 35

1. Wait until acute attack has stopped 2. Use prophylactic NSAIDs or low dose steroids until uric acid levels are normal 3. Adjust allopurinol dose according to renal function

Question 36

What lifestyle factors help in gout management?

Answer 36

Smoking cessation Lower consumption of highly processed foods Reduce alcohol consumption Increase water intake ->lots of people get a flare up of gout when on holidays because they don't drink enough water and too much alcohol

Question 37

Gout usually affects toes. Where does pseudogout usually affect?

Answer 37

Knee, can affect wrist but mostly knee

Question 38

Who is more likely to develop pseudogout?

Answer 38

Elderly females

Question 39

What are some of the causes of pseudogout?

Answer 39

Idiopathic Familial Metabolic

Question 40

What are some of the triggers of pseudogout?

Answer 40

Trauma Intercurrent illness

Question 41

What is important to note about sending off urate crystals to the labs?

Answer 41

They disintegrate very quickly so need to be sent off immediately

Question 42

Management of pseudogout?

Answer 42

NSAIDs Intra-articular steroids

Question 43

Polymyalgia Rheumatica is very difficult to diagnose as very similar to many other conditions. Which condition in particular if you suspected Polymyalgia Rheumatica would you also have to screen for?

Answer 43

Giant Cell Arteritis ->very important not to miss as risks of stokes and blindness associated with GCA,

Question 44

What is the most important part of a presentation which are indicative of polymalgai rheumatica?

Answer 44

SUDDEN onset of shoulder +/- pelvic girdle STIFFNESS

Question 45

What age do people tend to get polymyalgia rheumatica?

Answer 45

>70 ->rare <50 so be suspicous of underlying condition e.g. malignancy

Question 46

What are some of the features/symptoms of polymyalgia rheumatica?

Answer 46

ESR usually >45, often even 100 Anaemia Malaise Weight loss Fever Depression

Question 47

How is a diagnosis of polymyalgia rheumatica made?

Answer 47

No blood test or test for definite diagnosis Based on history, age >50, ESR >50 Will have a dramatic steroid response ->looks like many other conditions, DD = inflam joint disease, underlying malignancy, inflam muscle disease, hypo/hyperthyroidism

Question 48

Treatment for polymyalgia rheumatica?

Answer 48

Prednisolone Bone prophylaxis ->bone proph is because course of steroids is for 18-24 months and anyone on steroids for >5 months need bone protection