Crystal Arthropathy Flashcards
What is gout?
Gout is a syndrome characterised by: hyperuricaemia and deposition of urate crystals causing attacks of acute inflammatory arthritis; tophi around the joints and possible joint destruction; renal glomerular, tubular and interstitial disease; and uric acid urolithiasis.
What joints does gout most commonly affect?
The disease most commonly affects the first toe (podagra-first MTP joint), foot, ankle, knee, fingers, wrist, and elbow; however, it can affect any joint. Can affect pinna of ears
What is the cause of gout?
High urate levels
Hyperuricaemia is due to renal under-excretion of urate in 90% of cases and to over-production in 10%, although there is often an overlap of both.
What are the risk factors for gout?
Older age Male sex Menopausal status Consumption of meat, seafood, alcohol Use of diuretics Use of ciclosporin (cyclosporine) or tacrolimus Use of pyrazinamide Use of aspirin Genetic susceptibility high cell turnover state Adiposity and insulin resistance Hypertension Renal insufficiency Diabetes mellitus Hyperlipidaemia
What are the symptoms of gout?
Rapid-onset severe pain Joint stiffness Foot joint distribution Few affected joints Swelling and joint effusion Tenderness Tophi Erythema and heat over affected joint
What are some causes of over production of uric acid?
Malignancy e.g lymphoproliferative, tumour lysis syndrome Severe exfoliative psoriasis Drugs e.g. ethanol, cytotoxic drugs Inborn errors of metabolism HGPRT deficiency
What are some causes of under excretion of uric acid?
Renal impairment
Hypertension
Hypothyroidism
Drugs e.g. alcohol, low dose aspirin, diuretics, Cyclosporin
Exercise, starvation, dehydration
Lead poisoning
Lactic acid excess restricts uric acid excretion
What type of uric acid is found in gout?
Monosodium urate
What type of crystal is found in pseudogout?
Calcium pyrophosphate dihydrate (CPPD)
What enzyme is deficient in Lesch Nyan syndrome?
hypoxanthine-guanine phosphoribosyltransferase (HPRT)therefore produce more uric acid so get gout
What type of syndrome is Lesch Nyan?
X linked recessive
What investigations should be done for gout?
Arthrocentesis of joint to see if infection or arthritis
Ultrasound
Uric acid level-can be variable in acute phase, more useful when acute attack is settled
X ray of affected joint
Diagnosed also on clinical-history shows acute episodes of symptoms typically lasting seven to ten days then resolving
What are some differential diagnoses of gout?
Septic arthritis
Pseudogout
Trauma
Rheumatoid arthritis
What can an acute flare of gout be treated with?
NSAIDs
Colchicine-profuse diarrhoea, give if cant give NSAID
Steroids
Use these until urate levels normal
When would hyperuricaemia be managed?
Doesn't need treated if asymptomatic First attack not treated unless: Single attack of polyarticular gout Tophaceous gout Urate calculi Renal insufficiency Treat if second attack within 1 year
