Introduction & module overview
If asked to describe a typical gout sufferer, many people would paint a picture of a middle-aged man with a florid complexion and a bulging waistline. While this certainly points to some of the risk factors that make an attack of gout more likely, it is by no means the full story.
Gout is the most common form of inflammatory arthritis, affecting between two and three in every 100 people in the UK. The inflammation most commonly associated with the condition – although this is just one facet of the disease – results from uric acid accumulation, usually around a distal joint such as in the toes, fingers, ankles or knees. The build-up of uric acid crystals in the synovial fluid around a joint causes sudden flares of heat and swelling as the body tries to clear the affected site, and severe pain due to the nerve activation as a result of increased pressure in the surrounding tissues.
The uric acid accumulates because the level of purines in the body gets too high to be contained in the bloodstream. (Purines are a by-product of the metabolism of certain foods and drinks.) Unmanaged, gout can lead to long-term complications and significant disability.
Clinical phases
The person’s uric acid level is higher than normal, so while they do not have symptoms there is an increased risk of an acute episode
Pain and swelling affects (usually) a single peripheral joint
After the first attack has resolved, there is an increased risk of a second attack within a year. Chronic symptoms can develop within 10 years
Large deposits of crystals (tophi) form, creating irregular, firm nodules, which can lead to joint damage.
The global incidence of gout is on the rise, mainly because prevalence increases with age. It is more common in men over 30 years of age and postmenopausal women, with cases rare in those under 20 years of age. The most important risk factor for developing gout is hyperuricaemia, which usually stems from impaired renal excretion of uric acid, although the cause in around 10 per cent of people with higher than usual uric acid levels is due to over-production.
In rare cases, gout may present in the absence of hyperuricaemia and vice versa. Other risk factors include:
- Concurrent disease, notably chronic kidney disease, hypertension, diabetes, hyperlipidaemia and osteoarthritis
- Diet high in alcohol, sugary drinks, meat and/or seafood
- Being overweight or obese
- Family history of hyperuricaemia or gout
- Some medicines (e.g. diuretics, ciclosporin and low-dose aspirin).