Crystal arthropathies Flashcards
Characterised by ?
deposition of mineralised material within joints and peri-articular tissue
COMMON
Common crystal deposition diseases (3)
Monosodium urate - gout
Calcium pyrophosphate dihydrate (CPPD) - Pseudogout
Basic calcium phosphate hydroxy-apatite (BCP) – calcific periarthritis/tendonitis
2/3 of urate in body comes from
purine metabolism
urate excreted in ?
70% kidney
30% biliary tract
reduced renal clearance of urine is most common cause of?
hyperuricaemia
hyperuricaemia - overproduction
malignancies, tumour lysis, chemo patients (high cell turnover and break down)
- psoriasis and gout
- alcohol
- inborn erros or metabolism
hyperuricaemia - overproduction deficiency ?
HGPRT
hyperuricaemia - UNDEREXCTRETION (6)
- renal impairment
- hypetension
- hypothyroidism
- drugs - alcohol, aspirin
- exercise, starvation, dehydration
- lead poisoning
over indulgence in alcohol
Genetic problems? Lesch nyan syndrome deficiency?
- features of this syndrome
HGPRT
- X linked recessive
- self mutation
- gout
- renal disease
- aggressive and impulse behaviour
- intellectual disability
Gout is more common in?
men
Hypoxanthine-guanine phosphoribosyl transferase (HPRT) normally plays a key role in the ?
recycling of the purine bases, hypoxanthine and guanine, into the purine nucleotide pools.
Absence of HPRT
purine bases cannot be salvaged; instead, they are degraded and excreted as uric acid
- synthetic rates for purines is accelerated - compensates for loss - overproduction of uric acid
Classic history of gout?
more sun exposure, alcohol, dehydrated
Episodes often occur in what joint?
Often starts?
MTP
OVERNIGHT
Episodes often occur in what joint?
Often starts?
episodes last how long?
MTP
OVERNIGHT
5-7 days - erythema of skin, hot and shiny
Tophi are see over - what causes this?
bony surfaces
- white appearance during skin
- massive accumulation of uric acid
Investigation of gout
aspirate the joint
What would yo used under microscope for gout?
crystals
Management of Gout - acute flare
NSAIDs
Colchicine - diarrhoea
Steroids - I/A, I/M, oral
Management of Gout - HYPERURICAEMIA??
a 1st attack is not treated unless? (3)
Single attack of polyarticular gout
Tophaceous gout
Urate calculi
Renal insufficiency
-Prophylactically prior to treating certain
What do we not treat?
asymptomatic hyperuricaemia
Lowering uric acid - commonly used drugs? (4)
Allopurinol
Febuxostat - avoid in patients with cardiac history
Uricosuric agents e.g. sulphinpyrazone, probenecid, benzbromarone
Canakinumab
Rules for lowering uric acid levels? (3)
- 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 - (increase it up monthly)
really important in patients with gout to assess?
cardiovascular and lifestyle factors
Pseudogout - joint?
who does it typically effect?
flares are often?
knee
older women
erratic
triggers of Pseudogout
Trauma, Intercurrent illness
In pseudogout you see?
Chondrocalcinosis on an XRAY
Aspirating joint in Pseudogout - what will you see?
rhomboid crystals
hard to find
Management of Pseudogout? (3)
NSAIDs
I/A steroids (inter articular)
There are no prophylactic therapies
Polymyalgia Rheumatica is a?
close relationship with?
inflammatory condition of the elderly
- giant cell arteritis (high serum anaemia)
Polymyalgia Rheumatica - how many patients may have evidence of GCA
20%
Polymyalgia Rheumatica - symptoms (5)
female to male ratio?
sudden onset - shoulder +/- pelvic girdle STIFFNESS
- anaemia
- malaise, WL, fever, depression
- Arthralgia / synovitis occasionally
- usually in over 70’s
2:1
Polymyalgia Rheumatica - diagnosis
ESR greater than?
Compatible history Age > 50 ESR > 50 Dramatic steroid response 9n 48 hours No specific diagnostic test
Differential diagnosis of Polymyalgia Rheumatica? give examples of what it could be? (6)
- Myalgic onset Inflammatory joint disease
- Underlying malignancy
e. g Multiple myeloma, lung cancer - Inflammatory muscle disease (mysitis)
- Hypo/ hyperthyroidism
- Bilateral shoulder capsulitis (can present with stiff shoulders)
- Fibromyalgia
- look for temporal artery tenderness
Polymyalgia Rheumatica? - treatment (3)
under 65’s and over 65’s?
- Prednisolone 15mg per day initially - often start on that for 4 weeks
- 18-24 mth course
- Bone prophylaxis
in under 65’s - DXA scan
over 65’s - fractures - bone protection along with the steroids
. In the vast majority of people with gout, hyperuricaemia results from ?
reduced efficiency of renal urate clearance
