Gout

Description, causes, prevention, treatment and medicines

What is gout?

Gout is a common type of arthritis and has the unique distinction of being one of the most frequently recorded medical conditions throughout history. It is sometimes considered a ‘rich man’s’ disease because it is often associated with the intake of too much rich food and alcohol.

Uric acid

Gout occurs when there are abnormally elevated levels of uric acid in the blood and tissues. Uric acid is the end product of the metabolism of chemicals called purines that are found in many foods. Purines are also found naturally in the body. Normally, the body disposes of excess uric acid via the urine, but in people with gout uric acid accumulates in the body.

This can be due to reduced excretion of uric acid by the kidneys or to overproduction of uric acid by the body. This accumulation of uric acid may also cause kidney stones.

Gout attack

When uric acid accumulates in the blood and tissues it can crystallise out into a joint, forming a multitude of tiny, jagged, needle-shaped crystals. This triggers an intense inflammatory response that causes a painful arthritis attack called a gout attack.

This type of attack commonly strikes the base of the big toe, but other joints can be affected, including the instep, ankle, knee, wrist, elbow and fingers.

Gout symptoms

Symptoms of an attack include:

• sudden, intense pain in a joint;
• swelling, inflammation and a feeling that the joint is very hot;
• reddish discolouration;
• marked tenderness (this tenderness can be so intense that even a blanket touching the skin can be unbearable); and
• chills or fever, in some cases.

A gout attack usually strikes unexpectedly, but usually subsides in a few days with treatment. However, some people experience pain for several weeks. Gout attacks often re-occur and without the correct management, attacks may become more frequent.

You should contact your doctor if severe pain in a joint recurs or lasts more than a few days, especially if the pain is accompanied by chills or fever.

Hyperuricaemia

Some people may have high levels of uric acid in the blood (this is called hyperuricaemia), but have no arthritis pain. This sometimes happens to close relatives of gout sufferers. Many people with high levels of uric acid do not develop gout, while sometimes people with repeated gout attacks have normal or low levels of uric acid.

Who gets gouty arthritis?

Gout is roughly 9 times more common in men than women and is most common in middle-aged men. It is strongly associated with being overweight and having high blood pressure. Gout can also occur in women, more commonly after menopause.

Maori and Pacific Islander peoples tend to have high uric acid levels and are predisposed to gout. In Australia, the type of individual most commonly affected by gout is an overweight man who drinks large amounts of alcohol, is a regular meat-eater and who may have high cholesterol and high blood pressure.

Risk factors for developing gout

Uric acid is a by-product of the breakdown of certain foods in the body, and gout was once considered to be closely related to diet. It is now understood that inheriting it is the most common reason for gout to occur.

Certain medications, such as some types of diuretics, can also cause gout. Aspirin and niacin can also raise uric acid levels. Also, certain diseases can lead to an excessive production of uric acid in the body, including some leukaemias, lymphomas and some haemoglobin disorders.

Some studies have indicated an increased prevalence of abnormally low thyroid hormone levels (called hypothyroidism) in people with gout.

Aggravating factors

There are a number of conditions that can cause acute attacks of gout. These include:

• dehydration;
• injury to a joint;
• excessive intake of purine-containing foods;
• sudden starvation;
• heavy alcohol intake; and
• recent surgery (this may be related to changes in the body fluid balance because of fasting before surgery).

Tests for gout

Blood tests can be done to measure the amount of uric acid in the blood, although this may not be conclusive of gout.

Also, your doctor can insert a needle into the affected joint, remove some fluid from the area and examine this fluid for the uric acid crystals characteristic of gout. This can also exclude other problems (such as infection) being the cause of the painful swollen joint.

Prevention of gout

Preventing acute gout attacks is equally as important as treating the gout. Prevention of gout generally involves:

• maintaining adequate fluid intake to promote the excretion of uric acid;
• weight reduction, if necessary. This can be achieved by reducing dietary fat and calorie intake, which should be combined with a regular aerobic exercise programme. However, crash diets should be avoided as this can lead to an increase in uric acid levels through lowered uric acid excretion;
• dietary changes to reduce uric acid levels in the blood. You should avoid purine-rich foods such as shellfish, organ meats (liver, brains, kidney etc.), and anchovies and sardines. You should also limit the intake of dried beans and peas and yeast products; and
• reduction or elimination of alcohol consumption. Alcohol can cause uric acid levels to rise and can also have a diuretic effect that can add to dehydration and precipitate gout attacks.

Treatment of an acute attack of gout

• Pain relievers, such as paracetamol or other more powerful analgesics, are used to manage the pain.
• Anti-inflammatories, such as non-steroidal anti-inflammatory drugs (NSAIDs), are used to decrease joint inflammation and reduce the pain.
• If NSAIDs cannot be given because of an ulcer, colchicine may be used to settle an attack.
• Steroids may be given by mouth or injected into the joint to control an attack of gout.
• Aspirin must be avoided.
• Resting the joint, possibly in a splint, and applying ice packs may help.

Medicines to avoid recurrent attacks

• Allopurinol is used in long-term prevention of gout and decreases the body’s production of uric acid.
• Medicines may be used to increase uric acid passed in the urine. These types of medicines (uricosuric drugs), for example probenecid, assist in reducing the risk of recurrent attacks of arthritis, kidney stones and kidney disease.

People experiencing gout attacks should, however, avoid medicines containing aspirin as these can make gout worse.

Self-help for gout

When the affected joint is a big toe, a box or cage to keep the bedclothes off the toe may be helpful.