Gout is a type of arthritis (very different to the more common rheumatoid arthritis and osteoarthritis) caused by attacks of painful inflammation in one or more joints. The pain of a gout attack can be severe.
Causes of Gout
Gout is caused by the excess of a chemical in the blood called uric acid (urate). Uric acid is made in the body and is usually harmless and. Most is passed out with the urine and some from the gut with the stools (faeces). In people with gout the amount of uric acid in the blood builds up. From time to time the level may become too high and tiny grit-like crystals of uric acid may form. The crystals typically collect in a joint. The crystals irritate the tissues in the joint to cause inflammation, swelling and pain – a gout attack.
Some people have a high level of uric acid but do not form crystals or have gout. Also, rarely, some people with a normal level of uric acid have gout attacks. However, as a rule, the higher the level of uric acid, the greater the chance of developing gout.
Normally, there is a fine balance between the amount of uric acid (urate) made and the amount that is passed out in the urine and faeces. This keeps the level of uric acid in the blood in check. However, in most people with gout, the kidneys do not pass out enough uric acid and the blood level may rise. They are said to be under-excreters of uric acid. Their kidneys usually work otherwise normally.
In some people, the build-up of uric acid may due to other factors. For example:
- Drinking too much alcohol.
- Not enough vitamin C in your diet.
- Sugar-sweetened soft drinks high in fructose.
- Certain foods such as eating a lot of heart, herring, sardines, yeast extracts, or mussels.
- Some medicines such as ‘water’ tablets (diuretics), aspirin (at full painkiller dose – not low-dose aspirin used to prevent blood clots), and some chemotherapy medicines.
- Illnesses where the cells of the body have a rapid turnover. For example, severe psoriasis and some blood disorders.
- People with certain other conditions have an increased risk of developing gout. These include:
- High blood pressure.
- Kidney damage.
- Diabetes mellitus.
- Bone marrow disorders.
- Lipid disorders (especially hypertriglyceridaemia).
- Vascular disease.
- Enzyme defects such as hypoxanthine guanine phosphoribosyltransferase (HGPRT) deficiency and glucose-6-phosphate dehydrogenase (G6PD) deficiency.
How common is gout and who gets it?
Gout affects about 1 in 200 adults. Men are more commonly affected than women. A first attack of gout typically develops in middle age but it sometimes occurs in younger people. It tends to run in some families, as there is a family history of gout in about 1 in 5 cases.
Symptoms of gout
Gout usually occurs in attacks. An attack typically develops quickly over a few hours. It usually causes severe pain in one joint. The base of the big toe is the most commonly affected joint. However, any joint can be affected. Sometimes two or more joints are affected. Affected joints usually swell and the nearby skin may look red and inflamed. If left untreated, a gout attack may last several days but usually goes completely within 7-10 days. Less severe attacks can occur which may be mistaken at first for other forms of arthritis. Weeks, months or even years may go by between attacks. Some people only ever have one attack.
A gout attack can be very painful. However, other effects from gout are uncommon. Joint damage may occur in the case of recurring attacks. In a few people, uric acid crystals form kidney stones or may cause some kidney damage. Sometimes the crystals form bumps (tophi) under the skin. These are usually harmless and painless but sometimes form in awkward places such as at the end of fingers. Tophi occasionally become infected.
Diagnosis of gout
Gout is usually diagnosed if there are typical gout symptoms and a raised blood level of uric acid. If there is doubt as to the cause of the pain and swelling, a doctor may take some fluid out of a swollen joint. This is done with a needle and syringe. The fluid is looked at under the microscope. Crystals of uric acid (urate) can be seen in the fluid to confirm the diagnosis of gout.
Treatment for gout
If the patient is able to, then the affected limb (usually a leg) should be raised to help reduce the swelling. An ice pack held against the inflamed joint may ease the pain until the gout treatment medicines (below) start to work:
- The ice pack should be wrapped in a towel to avoid direct skin contact and ice burn.
- It should not be applied for long periods. (about 20 minutes)
- This can be repeated as often as required BUT one should make sure the temperature of the affected part has returned to normal before applying again.
A short course of an anti-inflammatory painkiller will quickly ease most gout attacks (within 12-24 hours). They are usually needed only for a few days until the inflammation and pain go.
More more than one anti-inflammatory painkiller should not be taken at a time unless specified by a doctor. For example, some people take low-dose aspirin every day (which is classed as an anti-inflammatory medicine) to prevent blood clots. Aspirin plus another anti-inflammatory medicine increases the risk of bleeding from the stomach. Therefore, a person who is already taking aspirin and develops gout, may be advised to take medicine to ‘protect the stomach’ if another anti-inflammatory medicine is needed in addition to aspirin. This should be discussed with the doctor.
Colchicine is an alternative medicine that eases gout attacks. It is usually only used if one has problems or side-effects with anti-inflammatory painkillers. Steroid tablets or injections can also reduce the pain and inflammation.
Prevention of gout attacks
Lifestyle measures and medicines can help to prevent gout attacks.
- If the patient is overweight, he/she should lose some weight
- A high uric acid level may be lowered a bit by avoding a high protein intake and foods rich in purines, such as liver, kidneys and seafood.
- Alcohol (if taken) should be avoided.
- Sugar-sweetened soft drinks, especially those containing fructose should be reduced or cut out all together.
- If on any any medication it should be checked whether they are a cause of gout. An alternative medicine may be available. A doctor will advise.
- Drinking plenty of water to avoid dehydration (up to two litres per day unless there is a medical reason why not to).
- Blood pressure check up at least once a year. High blood pressureis more common in people with gout.
With the help of lifestyle changes, many people only have an attack of gout every now and then. All that may be needed is to have some anti-inflammatory painkillers on standby to treat each attack.
For some people, attacks occur more often. In this situation, medicine can be taken to prevent attacks.
Allopurinol is used to prevent gout attacks
Allopurinol is a commonly used medicine to prevent gout attacks. Allopurinol does not have any effect during a gout attack and it is not a painkiller. It works by lowering the level of uric acid in the blood. It takes 2-3 months to become fully effective. One needs to take it every day to keep the uric acid level normal to prevent gout attacks.
As a general rule, regular allopurinol may be advised by the doctor in the following situations:
- two or more attacks of gout within a year.
- one or more tophi (described above).
- joint or kidney damage due to gout.
- kidney stones made from uric acid.
- Gout attacks while taking long-term medication that can cause gout.
Allopurinol, when started can sometimes cause a gout attack. For this reason it is not normally started during a gout attack. It is best to start it about 3-4 weeks after an attack has settled. Also, an anti-inflammatory painkiller is often prescribed for the first 2-3 months after starting allopurinol, just in case the allopurinol causes a gout attack. Once the level of uric acid has been brought down, taking allopurinol each day usually works well to prevent gout attacks. If side-effects do occur, other medicines with a similar action are sometimes prescribed.