Crystal arthropathies Flashcards
common diseases
monosodium urate- gout
calcium pyrophosphate dihydrate- pseudogout
Basic calcium phosphate hydroxy apatite- calcific periarthritis
TOPHUS- mass accumulation of uric acid
Purine metabolism
purines= Hypoxanthine=xanthin=plasma urate=urine uric acid
Hyperuricaemia
Over production: malignancy lymphoproliferative, tumour lysis Severe exfoliative psoriasis drugs eg ethanol HGPRT deficiency Under excretion: Renal impairment hypertension hypothyroidism drugs (alcohol, aspirin, diuretics) exercise, starvation lead poisoning
Lesch Nyan Syndrome
HGPRT deficiency X linked recessive intellectual disability aggressive behavior gout renal disease
Management of gout
Acute flare
NSAIDs
Colchicine
Steroids
Hyperuricaemia 1st attack not treated unless polyarticular gout tophaceous gout urate calculi renal insufficiency dont treat asymptomatic hyperuricaemia
lowering uric acid
xanthine oxidase inhibitor
uricosuric agents sulphipyrazone eg
IL-1 antagonist- canakinumab
rules for lowering uric acid
wait until acute attack settled
use prophylactic NSAIDS or low dose colchicine/ steroids
allopurinol can trigger acute attack of gout
adjust allopurinol dose according to renal function
pseudogout
more affect knee elderly females erratic flares idiopathic, familial metabolic triggers trauma, intercurrent illness
management of pseudogout
NSAIDs
I/A steroids
Polymyalgia Rheumatica
Polymyalgia Rheumatica-> Giant cell arteritis-> high ESR anaemia->
Polymyalgia Rheumatica
sudden onset of shoulder +/- pelvic girdle stiffness
anaemia
malaise; weight loss; fever; depression
arthralgia/ synovitis occasionally
Diagnosis
age
high ESR
dramatic steroid response
no specific diagnostic test
Ddx
Myalgic onset inflam joint disease underlying malignancy thyroid bilateral shoulder capsulitis fibromyalgia
treatment
prednisolone
bone prophylaxis- DEXA scan during the course of treatment with steroids
