Signs and Symptoms
The signs and symptoms of gout are almost always acute on clinical presentation, occurring suddenly and without warning. They include intense joint pain, inflammation, redness and swelling of the affected area. These symptoms often occur at night.
Gout usually affects the large joint of the big toe but it can occur in feet, ankles, knees, hands and wrists.
The urate crystals which deposit in joints of gout sufferers are formed because of the higher level of uric acid in the patient’s blood. The body produces uric acid when it breaks down purines, substances that are found naturally in the body as well as certain foods.
Normally uric acid is produced from purines in the liver. It enters the bloodstream and eventually passes through the kidneys, being excreted as urine. Otherwise, it is disposed of in the intestines where it is processed and broken down by bacteria. Sometimes the body either produces too much uric acid or the kidneys excrete too little uric acid. This can cause the formation of urate crystals in a joint or surrounding tissue. The crystals are needle-like in shape causing the pain, inflammation and swelling.
The normal level of uric acid in blood plasma of a healthy patient is below 6.8mg/dL. In concentrations of uric acid above 7mg/dL the blood becomes super saturated causing the formation of the monosodium urate crystals.
High levels of uric acid are associated with not only gout but also a number of other conditions. They can occur independently but may also develop one after the other if gout is untreated. These include:-
(a) Acute gouty arthritis.
(b) Chronic tophaceous gout and tophi. Tophi appear white or yellowish-white chalky modules which can protrude through the skin.
(c) Uric acid nephrolithiasis (kidney stones). Sufferers of kidney stones are more than 1000 times more likely to also be sufferers of gout than the general population.
Of patients that develop hyperuricemia (higher levels of uric acid in the blood), not all develop gout. Researchers have not yet determined the reason for this or why gout develops in certain joints but not others. More than 99% of primary gout cases are idiopathic. The remaining 1% is traceable to either two rare inherited enzyme defects that affect purine synthesis in the cells.
The risk of suffering gout is increased by the following:-
(a) Lifestyle factors:- Alcohol consumption and consumption of purine rich foods are contributing factors. Binge drinking particularly increases uric acid levels. A 2004 study showed that among alcoholic beverages, beer is the most strongly linked with gout, followed by spirits. Moderate consumption of wine does not appear to increase the risk of developing gout. Similarly the study showed a higher consumption of purine rich foods such as meat and seafood were associated with a significant increased risk of gout. However, purine rich vegetables did not increase the risk of gout. The consumption of dairy products appeared to have a protective effect against gout. A subsequent study in 2005 confirmed these results and found that total protein intake was not associated with increased uric acid levels. Gout is very uncommon in less developed countries. In 1952 it was said to be unknown in China, Japan and the Tropics, believed to be as a result of diet, however this has changed with the Westernisation of these cultures.
(b) Medical conditions:- Certain diseases and conditions make it more likely that a patient will develop gout. These include obesity, hypertension (high blood pressure), diabetes, arteriosclerosis (narrowing of the arteries) and hyperlipidemia (high levels of fat and cholesterol in the blood).
(c) Certain medications:- Medications such as diuretics inhibit the body’s ability to expel excess uric acid. Research has also shown that low dose aspirin, often taken to prevent heart disease, and anti rejection drugs prescribed for people who have undergone organ transplant, increase the risk of gout.
(d) Age and sex:- Gout occurs more often in men then in does in women primarily because women tend to have lower uric acid levels than men. After menopause, however, woman’s uric acid levels approach those of men leading to an increased incidence of gout in women at that stage of life.
(e) Exposure to lead:- Research has indicated that chronic occupational exposure to lead is associated with the build up of uric acid and a high incidence of gout. A 2002 study suggested that a persistent low level exposure to lead is sufficient to provide such an increased risk.
