Gout is common in New Zealand, with an estimated prevalence of 2.7% for the overall population and a prevalence of 3.75% in people aged 20 years or older.
Gout most commonly affects adult men (particularly after age 40) and is uncommon in women until after menopause. It is estimated to affect adult men 3.5-times more than women and is more common in people of Maori and Pacific Island descent and is less common in Asians.
Left untreated over time gout can lead to joint and kidney damage and, in conjunction with other risk factors such as high blood pressure and diabetes, can increase the risk of heart disease, stroke, and kidney failure.
Gout is caused by raised levels of uric acid in the blood (hyperuricaemia). Uric acid is produced naturally in the body. Normally it stays dissolved in the blood and is excreted by the kidneys as a component of urine.
Under-excretion or over-production of uric acid by the body can cause levels in the blood to be raised. When this occurs, crystals of uric acid can form and deposit in the joints causing gout. However, not all people with raised uric acid levels in their blood will develop gout.
A number of risk factors are related to the development of gout. These include:
- High alcohol intake
- A genetic predisposition
- High intake of foods rich in purines (eg: some seafoods and meats)
- Certain medicines eg: diuretics (fluid tablets)
- Injury to a joint
- Long-standing kidney disease.
Occasionally there is no obvious cause for an attack of gout.
Signs and symptoms
Gout develops quickly, often within 12 to 24 hours. Signs and symptoms of a gout attack include:
- Severe pain and tenderness in the affected joint
- Swelling of the affected joint
- The skin over the joint may feel hot and tight and may look shiny and red.
Some people may also experience nausea, a loss of appetite, and a slight fever.
Gout can be difficult to diagnose because the symptoms may mimic those of other conditions such as joint infection. In order to make an accurate diagnosis the doctor will examine the affected joint and take a full medical history. They will also assess the nature and duration of the symptoms experienced.
A blood sample may be taken to check for alterations in normal blood levels and a raised uric acid level. Results of this test may not always be helpful, however, as they often indicate normal uric acid levels during an attack of gout. This is likely to be because the excess uric acid has moved out of the blood and has settled as crystals in the joints.
In order to make a definitive diagnosis of gout the doctor may take a sample of fluid from the affected joint. This is performed using a local anaesthetic and involves inserting a needle inserted into the affected joint and removing a small amount of fluid. The fluid is then sent to a laboratory where it is tested for the presence of uric acid crystals. If they are present, then gout is confirmed. X-rays of the affected area may also be taken to check for joint damage.
Treatment and prevention
Medical treatment is aimed at relieving the pain and inflammation of acute attacks and preventing the occurrence of future attacks. Diet and lifestyle changes also help to prevent future attacks of gout.
Without treatment it may take up to a week for symptoms of a gout attack to subside. Attacks of gout can recur. At first, the time period between attacks can be as long as several months or even years. However, over time attacks tend to occur more frequently and tend to be more severe.
Treatment of acute attacks:
The more promptly that effective treatment is commenced, the more quickly the attack can be controlled. The different types of medications used include:
- Medications to reduce pain – particularly non-steroidal anti-inflammatory medications (NSAIDs). Taken early in the attack NSAID's can reduce the duration and severity of the attack. Paracetamol taken in conjunction with other medications can help in reducing pain. Aspirin should be avoided as it can reduce the amount of uric acid excreted by the body.
- Colchicine – this medication helps to block production of uric acid. It is most effective when taken early in an attack. However, it can have side effects such as diarrhoea if too much is taken. Dosage instructions should be followed carefully.
- Corticosteroids – such as prednisone may be given in tablet form to help reduce pain and inflammation. Corticosteroid injections directly into the joint may also be effective.
Drinking extra fluid (preferably water) while taking these medications is recommended. The affected joint should also be rested and elevated.
Preventing future attacks:
Preventing attacks of gout is as important as treating the symptoms of an acute attack. Ways in which gout can be prevented include use of medications and lifestyle changes.
Medications – the mainstay drug for people with gout is allopurinol, which acts to reduce uric acid production. People who cannot take allopurinol because of side effects or other reasons may be prescribed febuxostat, which also reduces uric acid production, or probenecid or benzbromarone, which work by increasing the excretion of uric acid by the kidneys.
In the initial stages of treatment with medications to prevent gout, attacks may occur more frequently and may be more severe. For this reason, the dosage of the medications may be low to start with, and is then gradually increased. These medications should only be discontinued on the advice of a doctor as stopping and starting them can also bring on an attack of gout.
Dietary modifications – changes in diet are aimed at restricting or avoiding foods high in purines. Purines are substances found in some foods and produce uric acid when broken down by the body. Foods high in purines include:
- Shellfish (pipis, paua, oysters, mussels) and fish roe
- Offal foods (brains, liver, kidney, tripe)
- Red meat (beef, pork/bacon, lamb)
- Yeast extracts (Marmite, Vegemite)
- Foods containing yeast (bread, beer)
- Oily fish (sardines, herrings, and anchovies).
Limiting alcohol intake – is also important. Alcohol causes the body to lose fluid (by increasing urine output and drawing water from the blood), thus increasing the uric acid concentrations in the blood. Beer is rich in purines so should be avoided.
Drinking plenty of non-alcoholic fluids – especially water (eight to 10 glasses a day) is recommended. This will help to flush the uric acid crystals out of the body. Drinks sweetened with fruit sugar (fructose) are best avoided.
Maintaining a healthy body weight – will help to reduce stress on affected joints and decrease the likelihood of developing gout.
If uric acid levels remain raised for long periods of time, or there are frequent recurrent attacks of gout, deposits of uric acid salts may appear around the affected joint. These are called tophi and appear as chalky coloured nodules. Tophi may also appear in other areas of the body such as the ears.
Recurrent severe attacks of gout and the development of tophi can cause permanent damage to the joints. Surgery may be required to restore joint function. This may involve joint replacement surgery.
Damage to the delicate filters within the kidneys and the development of kidney stones can also occur if uric acid levels in the blood remain raised for long periods of time. This in turn can impair kidney function.
In order to prevent the complications of gout it is important to treat gout attacks quickly and prevent gout attacks recurring by adopting the measures outlined above. It is also important to carefully follow the treatment instructions given by a doctor.
For further information and support contact your doctor, practice nurse, or:
Arthritis New Zealand
Postal address: Box 10-020, The Terrace, Wellington 6143
Free phone: 0800 663 463
Arthritis New Zealand (2015). Gout (Web page). Wellington: Arthritis New Zealand. http://www.arthritis.org.nz/information/forms-of-arthritis/gout/ [Accessed: 13/07/16]
Dalbeth N, et al. Gout in Aotearoa New Zealand: are we going to ignore this for another 3 years? N Z Med J. 2016 Jan 29;129(1429):10-3.
Ministry of Health (2015). Gout (Web page). Wellington: Ministry of Health. https://www.health.govt.nz/your-health/conditions-and-treatments/diseases-and-illnesses/gout. [Accessed: 13/07/16]
O’Toole, M.T. (Ed.) (2013). Gout. Mosby’s Dictionary of Medicine, Nursing & Health Professions (9th ed.). St Louis: Elsevier Mosby.
Winnard D, et al. National prevalence of gout derived from administrative health data in Aotearoa New Zealand. Rheumatology (Oxford). 2012;51(5):901-9.
Last Updated: July 2016