Crystal arthropathy Flashcards
How are crystal deposition diseases characterised?
deposition of mineralised material within joints and peri-articular tissue
3 common crystal deposition diseases
monosodium urate -> gout
calcium PYROPHOSPHATE dihydrate –> pseudogout
basic calcium phosphate hydroxy-apatite –> calcific periarthritis/tendonitis
Gout - appearance
1st MTP joint acute onset - over night red, shiny, acutely painful over bony prominences white flecks of crystal
how long does an attack of gout last?
7 to 10 days
Tophus
massive accumulations of URIC ACID
source of endogenous uric acid
purine degeneration and diet
link between uric acid and gout
hyperuricaemia leads to gout
overproduction causes of hyperuricaemia
malignancy drugs eg cytotoxic, ethanol severe exfoliative psoriasis inborn error of metabolism HGPRT enzyme deficiency
underexcretion causes of hyperuricaemia
renal impairment hypertension hypothyroidism drugs eg alcohol, diuretics exercise, starvation, dehydration lead poisoning
Cause of Lesch Nyan syndrome
HGPRT deficiency
inheritance of Lesch nyan syndrome
x-linked recessive
Symptoms of lesch nyan syndrome
gout renal disease self mutilation aggressive and impulsive behaviour intellectual disability
risk factors for gout
Henry 8th - HTN, diabetes, obese, cholesterol
sportsman - dehydrated
alcohol
diuretics
Prevalence of gout in UK
elderly men
oestrogen helps excrete uric acid
ageing eg diuretics, decreased renal function
Investigations for gout
high uric acid blood test? chronic?
ASPIRATION - crystals and exclude infection
managing an acute flare of gout
NSAIDS
colchicine
steroids I/A,I/M,oral
Side effect of colchicine
diarrhoea
When do you treat hyperuricaemia in the 1st attack of gout?
urate calculi
trophaceous gout
single attack of polyarticular gout
renal insufficiency
Treating hyperuricaemia in gout
2nd attack in a year
prophylactically prior to treating certain malignancies
Do you treat asymptomatic hyperuricaemia?
NO
lowering uric acid medications
allopurinol
febuxostat
sulphinpyrazone
canakinumab
How does allopurinol work to lower uric acid?
xanthine oxidase inhibitor
3 rules for lowering uric acid levels
wait until acute settled before introducing allopurinol
use prophylactic NSAIDS or low dose steroids/colchicine until urate level normal
adjust allopurinol depending on renal function
Pseudogout affects what joint?
KNEE
Who does pseudogout affect?
elderly females
idiopathic, familial, metabolic
triggers for pseudogout
trauma
intercurrent illness
Crystals in pseudogout
pyrophosphate
Management of pseudogout
NSAIDS
I/A steroid
What condition does polymyalgia rheumatica have a strong link to?
GCA
Symptoms of polymyalgia rheumatica
sudden onset of shoulder and/or pelvic girdle stiffness
anaemia
peripheral arthralgia/synovitis
malaise, weight loss, fever and depression
Who does polymyalgia rheumatica affect?
Females 2: male
Is ESR raised in polymyalgia rheumatica ?
yes
Diagnosis of polymyalgia rheumatica
compatible history
age >50 and ESR >50
dramatic response to steroids in 24-48 hours
diff diagnosis for polymyalgia rheumatica
polymyositis hyper/hypothyroidism fibromyalgia bilateral shoulder capsulitis underlying malignancy?
Treating polymyalgia rheumatica
prednisolone 15mg/day initially
18-24 month course
DEXA scan and bone prophylaxis
