Gout Flashcards
Define gout.
A disorder of uric acid metabolism causing recurrent bouts of acute arthritis caused by deposition of monosodium urate crystals in joints, and also soft tissues and kidneys.
Describe the epidemiology of gout.
Prevalence 0.2 %.
M:F = 10:1.
Very rare in pre-puberty and in pre-menopausal women.
More common in higher social classes.
More common in caucasians.
Peak incidence in males is between 40 and 60 years of age, in females it more often occurs between 60-70yrs.
Describe the pathogenesis of gout.
Hyperuricaemia is a prerequisite for gout, although gout only develops in 10-20% of individuals with hyperuricaemia.
Levels of uric acid may decrese during an acute episode.
Triggers for acute attack: Trauma Dehydration Certain drugs and foodstuffs Binge drinking.
What conditions can lead to increased uric acid in serum?
Uric acid in serum is increased in: Obesity High alcohol intake Hypertension Renal impairment Chronic diuretic use -eg bendroflumethiazide.
What conditions can gout occur secondarily in?
Overproduction of uric acid: Myeloproliferative disease Haemolysis Psoriasis Tumour lysis syndrome (renal failure due to rapid lysis of malignant cells) Excessive alcohol consumption.
Underexcretion of uric acid: Renal impairment Lead exposure High alcohol intake Chronic diuretic use
Drugs:
Ciclosporin, pyrazinamide (interferes with uric acid excretion).
What would a patient with gout describe in their history?
Acute attack.
May be precipitated by trauma, infection, alcohol, starvation, introduction or withdrawal of hypouricaemic agents.
Sudden excruciating monoarticular pain, usually the metatarsophalangeal joint of the great toe.
The symptoms peak at 24h and resolve in 7–10 days.
Occasionally, acute attacks present with cellulitis, polyarticular or periarticular involvement.
Attacks are often recurrent, but the patient is symptom free between attacks.
What may be found on a patient’s skin that is presenting with Gout?
Trophi
(Deposits of urate)
Found in soft tissues, e.g. ear pinnae, hands and elbows.
What investigations would you perform for patient that had suspected gout?
Clinical features are often sufficient to make diagnosis.
Blood urea and creatinine should be checked to exclude renal impairment.
Synovial fluid aspirate:
Negatively birefringent, needle shaped uric acid crystals are found on polarising microscopy in synovial fluid/discharge from trophi
How would you manage a patient with gout?
Acute attack
NSAIDS (Colchicine if NSAIDS are contraindicated.
Intra-articular corticosteroids.
Intramuscular ACTH for difficult cases.
How would you manage a patient with gout?
Prevention of recurrent episodes
Advice
Lose weight, limit dietary intake of alcohol and red meat.
Allopurinol
Blocks xanthine oxidase is most commonly used drug.
Uricosuric drugs, e.g. probenicide and sulfinpyrazone are useful if px intolerant to allopurinol.
NSAIDS (initially)
Why should NSAIDS be given when allopurinol or uricosuric drugs are started for gout?
They are associated with increased risk of flare up of gout.
What complications might you expect for a patient suffering gout?
Renal failure,
urate urolithiasis,
urate nephropathy.
Secondary infection or ulceration of tophi.
What prognosis would you expect for a patient with gout?
75% have second attack within 2 years.
Prophylactic treatment often necessary in long term.
