Fever, malaise, leucocytosis and elevated inflammatory markers
In females, the first attack may be polyarticular, typically in the hands with gouty tophi
Incidence of gout increases with age, in females rarely occurs before menopause
Clinical features:
Monoarticular involvement of the foot or ankle (especially the first metatarsophalangeal MTP joint)
Previous similar acute arthritis episodes
Rapid onset of severe pain and swelling (reaching a peak in the intensity of pain and swelling within 24 hours)
Erythema
Tophi
Strong family history of gout
Cardiovascular disease and hyperuricaemia in males or postmenopausal females.
Risk Factors
Those with comorbidities including hypertension, chronic kidney disease, dyslipidaemia, type 2 diabetes and obesity
Those in a catabolic state (e.g. sepsis) or are dehydrated are at an increased risk of developing an acute attack
Often occurs during or immediately following hospitalisation
Strong family history of gout
Medications that inhibit renal excretion of uric acid (e.g. thiazide diuretics, loop diuretics (see Diuretics), ciclosporin)
Consumption of purine-rich foods, alcohol or fructose-sweetened drinks
Disorders involving high cell turnover (e.g. haematological malignancies, severe psoriasis)
Diagnosis/Investigations
Aspiration of an affected joint or bursa is the gold standard for confirming a diagnosis of gout
Measure serum uric acid concentration
Typically occurs when serum uric acid > 0.42 mmol/L (7 mg/dL)
Measure kidney function
Clinical diagnosis is supported by:
Monoarticular involvement of the foot or ankle or MTP joint
Previous similar acute arthritis episodes
Rapid onset of severe pain and swelling (reaching a peak in the intensity of pain and swelling within 24 hours)
Erythema, tophi
Strong family history of gout
Cardiovascular disease and hyperuricaemia in males or postmenopausal females
A plain X-ray of the joint is useful to identify joint damage due to gout and its presence is an indication for urate-lowering therapy
Management
Ideally diagnosis by aspiration should be made prior to starting urate lowering therapy
Improvement with colchicine can also happen in pseudogout
Overview of management
Analgesia for acute gout
Discuss lifelong urate-lowering therapy and start using a treat-to-target approach
Modify existing medications thought to be contributing
Acute Gout
It is safe to start or modify urate-lowering therapy during treatment of an acute attack
Corticosteroids local or oral have a lower incidence of adverse effects than oral NSAID therapy
Prednisolone (or prednisone) 15-30 mg orally daily until symptoms subside typically 3-5 days
Oral NSAIDs
Celecoxib 100-200 mg orally daily in 1 or 2 divided doses until symptoms subside
Ibuprofen immediate-release 200 to 400 mg orally, 3 or 4 times daily until symptoms subside
Naproxen immediate-release 250 to 500 mg orally, twice daily until symptoms subside
Naproxen modified-release 750 to 1000 mg orally, daily until symptoms subside
Oral colchicine has a small therapeutic window with risk of toxicity and adverse effects at higher doses; unlikely to be effective if not started within 24 hours of an attack
Colchicine 1mg orally initially, then 0.5 mg 1 hour later, as a single one-day course
Often used together with an NSAID (above) for symptom relief until the flare resolves
Avoid in patients with kidney impairment
Chronic Gout
Target serum uric acid concentrations
Nontophaceous gout: <0.36 mmol/L (6 mg/dL)
Tophaceous gout, chronic arthroplasty or frequent attacks: <0.30 mmol/L (5mg/dL) initially until total crystal dissolution and resolution of gout then <0.36 mmol/L (6 mg/dL)
Allopurinol 500 mg orally daily then increase the dose by 50 mg every 2 weeks or by 100 mg every 4 weeks up to a maximum daily dose of 900 mg to achieve the target serum uric acid concentration (above)
Avoid combination of allopurinol with either azathioprine or mercaptopurine
Skin rash is the most common side effect of allopurinol
Starting or increasing urate-lowering therapy is associated with a high risk of gout flare, so flare prophylaxis is recommended with colchicine 500 mcg daily for at least 6 months; reduce dosage in kidney impairment or in people who experience diarrhoea
Consider adding if not reaching target serum uric acid concentration despite allopurinol adherence:
Probenecid 250 mg orally twice daily for 1 week then increasing to 500 mg twice daily; then increase the daily dose by 500 mg every 4 weeks to achieve the target serum uric acid concentration (maximum 2 g daily in divided doses)
If allopurinol not tolerated use:
Febuxostat 40 mg orally daily for 2 to 4 weeks; then increase the daily dose by 40 mg every 2 to 4 weeks to achieve the target sesrum uric acid concentration. Maximum daily dose 120 mg