Understanding Gout
Introduction
A description of gout
Anyone who has suffered gout will recognize the description, given by a physician, Thomas Sydenham, of his own attacks, as long ago as 1683:
The victim goes to bed and sleeps in good health. About 2 o'clock in the morning, he is awakened by a severe pain in the great toe; more rarely in the heel, ankle or instep. This pain is like that of a dislocation, and yet the parts feel as if cold water were poured over them. Then follows chills and shiver and a little fever. The pain which at first moderate becomes more intense. With its intensity the chills and shivers increase. After a time this comes to a full height, accommodating itself to the bones and ligaments of the tarsus and metatarsus. Now it is a violent stretching and tearing of the ligaments-- now it is a gnawing pain and now a pressure and tightening. So exquisite and lively meanwhile is the feeling of the part affected, that it cannot bear the weight of bedclothes nor the jar of a person walking in the room.
Gout has an even longer history than this, with evidence of gout in ancient Egyptian skeletons from as long as 4000 years ago. Hippocrates, he of the famous oath taken by newly-qualified doctors, already wrote of gout in around 400 BC.
The next few paragraphs will try to provide answers to some of the commonly asked questions about gout, aiming to make this painful condition and its treatment more comprehensible to its sufferers.
Who gets gout?
Anyone! While gout has traditionally been associated with drinking a lot of alcohol, eating a lot of meat, and other indulgences, this is by no means necessary and most people who suffer gout nowadays are just ‘average’.
Gout is unusual before the age of about 30 years, and more common in men (almost 4 times as common in men as in women), but this favouring of men tends to even out with age, with the problem affecting women increasingly after the menopause. Overall a little over 1% of men will suffer gout.
It is true that some people will be more likely to get gout because of what they eat or drink, or because of drugs they have to take for other conditions, or because it runs in the family.
Some of these factors might be possible to modify after discussion with a doctor, but no one can change their parents! The apparent link between certain foods and gout may be at least partly due to the association of such diets (e.g. rich in red meat) with large alcohol consumption.
In discussing how to prevent gout later, we will make a distinction between common primary gout, which is largely determined by family genes, and rarer secondary gout, where an underlying alternative cause for the problem can be identified.
The gout attack (‘acute gout’)
Most people who suffer gout would use much less elegant language than Dr Sydenham to describe the severe pain that they suffer! The description he gives is nevertheless very accurate. For reasons that are unknown, attacks often do start in the early hours of the morning, often waking the patient, with increasing pain over a few hours.
People rarely describe having a fever or a temperature, but the attacks do most commonly occur in the big toe (more than 50%) or ankle and in-step.
Other joints can be affected (knee, elbow, wrist, hand joints), but it is unusual to have gout affecting the hip, for example, or shoulder. The swelling is usually very marked, and if the foot is involved, the whole foot is often affected, so that it is difficult to tell that the problem stems from the big toe. It is almost always accompanied by redness (‘erythema’) and warmth, the area feeling hot to the touch, and extremely tender, to the extent that even the pressure of the bed clothes can be unbearable. It will be very difficult to walk, and almost impossible to take weight on the affected foot.
What happens after ‘acute gout’?
Once upon a time, there was no effective treatment for gout, although doctors were often unwilling to admit as much. We therefore know that if nothing is done about an attack of gout, the pain and swelling peak after around 24 hours, are at their most severe for a couple of days, and then gradually improve over 7 to 10 days.
As the swelling and redness disappear, the overlying skin sometimes flakes, leaving a trail of dead skin on the floor or in the bed, like scales. By 2 weeks after the attack started everything looks and feels back to normal. Doctors refer to this period after an attack, or, pessimistically, between this attack and the next, as the ‘intercritical period.’
Will it happen again?
Once someone has had one attack of gout, there is a good chance that it will happen again (to about 80% of people within 2 years), but it is impossible to predict how often or when. As we will see below, this is very important to appreciate when discussing the different types of treatment. If attacks occur very infrequently, we would be thinking about treatment very differently from someone who has attacks every few weeks.
Recurrent attacks
A small number of people have attacks frequently. As mentioned above, there may be identifiable reasons for this which can be modified, but regular medication may be required to prevent recurrent attacks. If attacks are recurrent and no treatment instituted the attacks tend to become more frequent (the intercritical period becomes shorter) and can involve more than 1 joint at a time (‘polyarticular gout’).
Chronic tophaceous gout
An even smaller number of people develop something called chronic tophaceous gout. As we will discuss, gout is usually associated with high levels of a chemical called uric acid in the blood. If uric acid levels are very high for many years this can cause not only the attacks of gout which we have described, but the uric acid can be deposited in a form outside the joints (called in medical terminology ‘extra-articular’gout, meaning outside the articulation or joint).
Tophi are deposits of a form of uric acid under the skin as a white, cheesy material, most commonly in the ear lobes and behind the elbows, but can occur almost anywhere.
These deposits are not usually painful, but are unsightly and can get in the way. If large, or if they catch on things, they can leak their cheesy material, which is messy, and the tophi can become infected and painful. Most importantly, the presence tophi means that similar deposits are occurring unseen within the body, such as in the kidneys, where they can cause damage.
If tophi occur it is therefore important to look at measures which lower the level of uric acid in the blood and so reverse this process. In people who suffer recurrent attacks of gout, and who do not have treatment to lower the blood uric acid level, it is estimated that 12% of them will develop tophi in the next 5 years, and 20% over 20 years. Conversely however, it is therefore important to realise that most people who have recurrent attacks of gout, do not go on to get tophaceous gout.
Another important manifestation of extra-articular gout is kidney stones. There are many types of kidney stone, but chemical analysis allows a medical laboratory to determine if a stone contains uric acid. If so this would therefore suggest the need to look at and lower the uric acid level in the blood.
Extra-articular gout can cause damage to the kidneys even without the formation of stones. Such kidney damage will be detected by blood tests of kidney function. However, these can only determine that kidney damage is present, not what causes it, and again, there are very many other causes of kidney damage other than a high uric acid level in the blood.
This is a difficult situation to interpret as kidney damage is itself often associated with failure to efficiently excrete excess uric acid in the urine. As a result the uric acid level rises in the blood. Faced with blood tests showing both a high uric acid level and a degree of kidney impairment it can be impossible to determine which came first.
