Gout is a clinical condition that is very common and is characterised by painful inflammation of the joints. It commonly affects the big toe but can be seen elsewhere as well in more severe cases. The main feature of gout is the deposition of uric acid crystals in the joints. It is more common in men and affects 1 to 2% of the population of the Western world.
This article will cover the epidemiology, clinical features and management of this condition and provide you with information on gout.
Gout is one of the commonest joint diseases in the world and studies have estimated that around 4 million people in the United States suffer from this condition. In addition it appears that the incidence and prevalence is rising. It is postulated that this is because of dietary habits and with the increased number of prescriptions handed out for diuretics. As was previously mentioned, this clinical condition is more common in men but its prevalence rises in women who are postmenopausal.
Why does gout occur?
During normal body metabolism, purines (present in foods) are broken down and uric acid is produced which is excreted by the kidneys. However, sometimes the uric acid production can exceed the amount that can actually be expelled from the body. Such a condition is called hyperuricaemia.
As a result of this, uric acid can precipitate and deposit in the joint tissues (cartilage) causing swelling and pain. Uric acid commonly precipitates as crystals which appeared like thin needles under the microscope. Over time these crystals clumped together to form ‘tophi’ which can then put pressure on the joints causing pain and decreased mobility. Damage to the joint can occur over time which is similar to other forms of arthritis.
What are the risk factors for the developing gout?
There are a number of risk factors that make patients more prone to developing gout and these include –
- Using water tablets – Thiazides
- High blood pressure or diabetes
- Diseases of the blood such as leukaemia
- Kidney disease
- Excessive alcohol intake
The commonest site of gout attacks the ball of the great toe. The area is often red and inflamed, hot to touch, tender and painful when attempted to move the joint. The skin over the joint can also be rather shiny.
Other than the great toe, gout can also affect the ankles, knees, fingers, wrists and elbows. Involvement of many joints together is called polyarticular (poly = many) gout.
Upon examination, other than the changes described above, small swellings may be seen on the surface of the skin which are actually accumulated uric acid crystals. These are tophi. The common site appearance of these is on the cartilage of the ear. In rare cases, it may be deposited on the eyelids. During an acute attack of gout, patients may have a mild fever as well.
Tophi in the ear cartilage
There are a number of different tests that can be performed to confirm gout but on many occasions is obvious on clinical examination. Below are lists of tests that can be performed –
1. Blood tests – These include measuring kidney function and uric acid levels in the blood. During an acute attack of gout, the white blood cell levels may be elevated. However, it must be noted that having a high serum uric acid level in the blood does not automatically indicate that the patient has gout unless it is accompanied by clinical features suggestive of it.
2. Synovial fluid examination – In patients who have gout affecting one joint, taking a small amount of fluid out of the joint using a fine-needle is a useful test to confirm the diagnosis. Once the fluid is taken out it is examined under a microscope to look for crystals of uric acid. Classically, the uric acid crystals are negatively birefringent (which helps compare it to pseudogout).
3. Urine examination – Examination of uric acid content in urine that is collected over a 24-hour period can help aid making a diagnosis.
4. X-rays of the joints – Unfortunately, x-rays of the joints are not diagnostic of gout. While it may be early changes that are seen in patients who have long-standing gout, it is rare for any characteristic changes to be seen in early stages of gout. The changes that are seen on x-ray are different to those seen in other forms of arthritis such as involvement of the space outside the joint capsule and normal appearance of the joint space (as compared to osteoarthritis where the joint spaces are obliterated)
5. Other tests – While the tests above are usually sufficient to make a diagnosis of gout, certain special tests may also be performed such as an ultrasound examination of the joint and occasionally more advanced imaging such as a CT scan or MRI.
There are a variety of treatments are available about which depend primarily on the stage of gout.
Acute attack of gout
When patients suffer from an acute attack of gout, pain is the primary symptom. In such cases painkillers are prescribed such as non-steroidal anti-inflammatory drugs. These drugs can include ibuprofen or diclofenac sodium.
However, these painkillers do not entirely get rid of inflammation that is present in the joint. In order to achieve this, colchicine is prescribed. This is usually given for a period of 5 to 7 days but sometimes patients may develop side-effect such as nausea and diarrhoea which required them to be stopped prematurely. These days however colchicine is reserved as a second line treatment after using non-steroidal drugs.
Sometimes, the above treatments may not be useful or helpful to patients and the pain may persist. In such cases, steroids may be injected into the joint that significantly reduces inflammation and pain.
Of the treatments discussed above, non-steroidal anti-inflammatory drugs are now the first line of treatment. They are usually prescribed along with drugs that protect the lining of the stomach such as proton pump inhibitors like omeprazole.
This refers to patients who have recurrent attacks of gout or have long-standing gout. The aim of the treatment in chronic gout is to keep the uric acid levels low. While this can be achieved by avoiding drugs that can increase the uric acid levels, drugs such as allopurinol and probenecid are useful at keeping the uric acid levels low and preventing acute attacks of gout.
Unfortunately, gout can bring with it significant amount of pain which can significantly affect the quality of life of patients. Studies have linked gout to a higher risk of deaths from heart disease. However, treatments are very effective and gout can be easily kept under control.
Gout is an inflammatory condition of the joints characterized by the position of uric acid crystals in them. Treatments are simple and effective and helps reduce the pain and swelling. The condition however can become chronic and over time can affect the quality of life of patients.