Gout

What is it?
Gout is a condition caused by the collection of needle-like uric acid crystals in one or more joints. This causes inflammation, swelling, and severe pain. The most frequently affected joint is the big toe. Other joints that are often affected include the hands, wrists, knees, and feet. Attacks of gout may occur several times a year and last for several days. Some people can develop long-term gout. Gout may also form lumps called tophi under the skin, and it may also accumulate in the kidneys, producing kidney stones and leading to kidney damage.

Increased levels of uric acid occur following the breakdown of purines, found in cellular DNA and in many foods. Uric acid is normally carried in the blood and removed from the body in the urine.

High uric acid levels are known as hyperuricaemia. This can occur for three reasons:

If production of uric acid is increased by the body
A person eats food high in purine

If the Kidneys cannot remove enough uric acid from the body

Gout develops more often in men than in women and is more common in adults. People with type 2 diabetes, obesity, sickle cell anaemia, and kidney disease have an increased risk of developing gout. Drugs such as cyclosporine, thiazide diuretics, and salicylates (aspirin) can interfere with uric acid excretion as can an excess of alcohol. In rare instances, a person may inherit a decreased ability to breakdown purines and so be more likely to develop gout.

Gout must be distinguished from conditions that can cause similar symptoms:

Pseudogout, a condition caused by calcium pyrophosphate crystals
Septic arthritis (caused by an infection in a joint)
Rheumatoid arthritis (an autoimmune arthritis)
Osteoarthritis (wear and tear)

The treatments of these conditions are different to those used in gout.

What tests are used?

Synovial fluid analysis – Fluid taken from the joint is examined for the presence of needle-like uric acid crystals, other types of crystals, and for signs of infection.
Uric acid - to detect high levels in the blood.
Kidney function tests - may be used to look for evidence of kidney damage.
Sometimes other tests, such as an RF(rheumatoid factor) or an ANA(anti-nuclear antibody) test may be requested to rule out other causes of arthritis symptoms.
A blood culture and/or synovial fluid culture may be requested if septic arthritis (arthritis due to an infected joint) is suspected.

X-rays of the affected joints may show uric acid deposits and damage from gout.

What treatments exist?
The goals of treatment are to ease pain and inflammation and to reduce uric acid levels. Low uric acid levels make future attacks less likely and decrease the chance of further joint or kidney damage.

During attacks you may be treated with nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen or naproxen to relieve pain and inflammation and if necessary you may be treated with steroids.

Drugs, such as probenecid or sulfinpyrazone, which lower uric acid, and allopurinol, which blocks the enzyme that produces uric acid, may be used to decrease the number and severity of future attacks.

Patients can also make lifestyle changes to minimize gout attacks. Some examples include drinking less alcohol, eating only moderate amounts of high-protein foods, and drinking more water to help the kidneys flush the uric acid out of the body.