Crystal arthritis Flashcards
What crystal causes gout
Monosodium urate/uric acid
What crystal causes pseudogout
Calcium pyrophosphate dihydrate
What causes gout?
Over-production of uric acid, or underexcretion (abnormal renal handling). Can be a combination of both.
What is uric acid a product of
Breakdown of purine bases
What can cause overproduction of uric acid
Excess dietary purines (ie proteins, shellfish, red meats) alcohol abuse, myeloproliferative disorder, and lymphoproliferative disorder
What can cause underexcretion of uric acid
Renal disease, polycystic kidney disease
Who is gout most common in?
Men over 40, and post-menopausal women. Especially prevalent in patients with comorbidities
Name predisposing factors for gout
Immediate post-op Myocardial infaction Stroke Fasting Alohol abuse High purine intake Local infection
How can acute gout present?
Extreme pain, joint swelling, shiny skin, redness and warmth. Usually one joint but can be multiple.
What joints are most commonly affected by acute gout
1st MTPJ most common, but can be ankles, knees, wrists and hands.
Do acute gout attacks end by themselves
yes
What is chronic gout
Occurs when patients have longstanding hyperuricemia with many gouty flares. May see neuropathy, uric acid stones in urinary tract\
how should synovial fluid be analysed?
Aspiration of symptomatic joint, examined under a microscope in polarised light. Gram stain and culture to rule out infection.
What will blood tests yield?
Usually raised serum uric acid but can appear normal. + ESR, CRP, WCC
What will the joint fluid analysis show if the patient has gout
WCC present, culture if infection present.
URIC ACID RAISED> looks like little blue needles.
What are the four aspects of patient management
Education, low purine diet, reduced alcohol and weight reduction
How can acute gout attacks be treated?
Rest and ice, NSAIDs or COX II inhibitors, oral steroids, local steroid injection, oral colcicine.
How can intercritical gout be treated?
DIet, alcohol, colcicine prophylaxis, urate lowering drugs (allopurinol) . COnsidered intercritical if 2+ attacks per year.
How does allopurinol work
It is a xanthine oxidase inhibitor
WHat are predisposing factors for pseudogout?
Hypothyroidism, hyperparathyroidism, haemachromatosis, acromegaly and gout
What is the prevalence of pseudogout?
Much less common than gout, but more common in the elderly.
What is the proper name for pseudogout?
Calcium pyrophosphate disease (CPPD). Pseudogout refers to acute synovitis within this
What are the two types of CPPD
Acute synovitis, experiencing pain, swelling, stiffness.
Chronic pyrophosphate arthropathy (gradual onset of pai, akin to osteoarthritis)
Can also involve asymptomatic chondrocalcinosis
What does synovial fluid analysis of CPPD show
Under polarised light examination, the CPPD crystals show as small rhomboid/rod shaped crystals. Examination should include gram stain and culture to rule out infection
What are the radiographic anomalies of CPPD
Changes in osteoarthritis and associated with chondrocalcinosis
how is pseudogout treated
Analgesia, joint aspiration, joint injection with steroids anf colcicine. No prophyaxis, but lifestyle advice includes weight loss, physio, pain control, or maybe joint replacement.
