Top tips on gout
Musculoskeletal medicine GPSI Dr Louise Warburton’s essential advice on spotting and managing gout.
Musculoskeletal medicine GPSI Dr Louise Warburton's essential advice on spotting and managing gout.
1 Be prepared to see more cases of gout. Gout is a common cause of arthritis in men over 40 and postmenopausal women. In an RCGP national morbidity survey in 1982, 2.7/1,000 patients visited their GP with an episode of gout. The incidence of gout is rising because of the explosion of obesity in the population, so be prepared to see more of it, especially in the run-up to Christmas. Fructose-sweetened soft drinks are also associated with increased risk of gout.
2 Look out for the less classical symptoms. Classically gout presents as an attack in the early hours of the morning, causing pain and swelling in the first metatarsal joint – 70% of attacks occur in this joint. But it is worth remembering that gout can affect the ankle, knee and joints of the foot as well. So, in the case of an elderly patient with a red, hot swollen foot, the differential diagnoses can be both infection and gout. I have also seen gout and pseudogout in the wrist joint, especially in elderly women.
3 Diagnosis can be especially tricky in older patients. An acute attack of gout will cause a fever, anorexia and malaise. Blood tests will reveal a raised ESR and CRP, sometimes a thrombocytosis and a raised white cell count. In elderly patients it can be difficult to differentiate between cellulitis, gout and pseudogout, even on blood tests.
4 Remember one normal uric acid level test does not exclude gout. We all know that gout is caused by deposition of urate crystals in joints. Usually this happens because of hyperuricaemia, but can happen in individuals with a normal urate level. In fact, one study found the prevalence of patients with acute gout who had normal uric acid levels at diagnosis was 12%, but 81% of these patients subsequently developed raised uric acid levels, at a median of one month after diagnosis. So we cannot rely on a single uric acid level to help us with diagnosis, but a level taken at the time of attack and another a month later can be more helpful.
5 Avoid aspirating the joint unless you are an expert. Classically the textbooks tell us to aspirate joint fluid from the inflamed joint and look for uric acid crystals, which are negatively birefringent under polarised light microscopy. But how many of us have actually managed to do that?
The joint fluid has to be still fresh and taken straight to the laboratory if the crystals are to be seen. I have only once managed to aspirate fluid – from an ankle joint – in general practice and get a result back that showed crystals of uric acid (although it was very satisfying). My advice would be to avoid aspirating unless you are an expert and can access the lab quickly.
6 Other pointers can help in diagnosis. Other clues to a possible diagnosis of gout are comorbid factors that can co-exist with hyperuricaemia. Hyperuricaemia occurs in metabolic syndrome and diabetes, and in those with renal failure; therefore the risk factors for gout include:
• male sex
• family history
• central obesity
• alcohol consumption
• renal insufficiency
• metabolic syndrome
• treatment with diuretics.
Look for these co-existing morbidities. With nGMS and the QOF, most of our patients will have had their blood pressure measured and a large proportion of those with hypertension will have had lipids and glucose checked as well. Conversely, in a patient with a new diagnosis of gout, look for these other comorbidities. If they haven't already been checked, arrange for fasting glucose, lipids and blood pressure, weight and waist measurement. Gout can be a marker for cardiovascular disease and diabetes.
7 First-line treatment is NSAIDs; steroids can be useful, as can colchicine, but side-effects can be a problem. The mainstay of drug treatment is NSAIDs – initially at the highest licensed dose and tapering off as the attack settles.All the textbooks mention colchicine – I find that it works but has a high level of unpleasant side-effects (diarrhoea and vomiting). Colchicine can be useful in preventing gout when allopurinol is started – use a dose of 500µg twice or three times daily and this prevents the side-effects but prevents acute gout. Don't use colchicine in patients of reproductive age unless they are using reliable contraception.
Steroids work very well and are more pleasant to take. Injections of steroid into an affected joint or bursa can work quickly and very effectively. I use 40-80mg of methylprednisolone in an ankle or knee, or 25mg hydrocortisone in a smaller joint such as the metatarsophalangeal joint. Oral steroids in a dose of 20mg of prednisolone daily, for four to five days, are also effective.
8 Conservative treatment options include changing diet and weight loss. Dietary restrictions that result in loss of weight will lead to a reduction in gout. Low-purine diets – reduction in meats, patés, fish roe and some oily fish – are effective to some extent. Patients should also avoid fructose-sweetened soft drinks. Apparently cherries can help to relieve acute gouty attacks because they contain anthocyanins, which have a similar effect to cox-2 inhibitors.
I give my patients a copy of the Arthritis Research Campaign's patient booklet on gout.
9 Aim to reduce the uric acid levels to 300mg/l or less. I usually start allopurinol in patients with more than three attacks of gout per year or very high urate levels. Remember to always use an NSAID or colchicine when allopurinol is started as it can precipitate an acute attack of gout. I usually ask patients to take an NSAID for about two weeks when the allopurinol is started.
I use doses of 50-300mg of allopurinol in most patients to reduce urate levels to normal, increasing to 600mg in exceptional cases. I always start at a low dose of 50mg in severe renal impairment and titrate up the dose of allopurinol until normal urate levels are achieved. Aim to reduce the uric acid levels to 300mg/l or less.
10 Remember to look for gouty tophi to exclude late-onset rheumatoid arthritis. Don't forget that gout can turn into a chronic condition that mimics inflammatory arthritis (called polyarticular gout). The patient will experience chronic joint pain in many areas of the body, with no pain-free intervals and acute synovitis. Look for gouty tophi to diagnose this and differentiate from late-onset rheumatoid arthritis.
Dr Louise Warburton is a GP in Telford, Shropshire, and a GPSI in rheumatology and musculoskeletal medicine for Telford and Wrekin PCT
Competing interests: none declaredGout Gout