Gout in Humans

Description

Gout is a common form of inflammatory arthritis, a condition affecting the joints and musculoskeletal system that causes intense pain, swelling and stiffness in a joint. Gout attacks can come on quickly and keep returning over time, slowly harming tissues in the region of the inflammation.

It is the most common form of inflammatory arthritis in men and although it is more likely to affect men, women become more susceptible to it after menopause.

The condition is characterized by sudden and severe pains, redness, and tenderness in the joints, most classically in the base of the big toe. Gout symptoms occur when uric acid is deposited in the form of needle-like crystals in tissues and fluids within the body. The body views these crystals as foreign and white blood cells infiltrate the joint causing inflammation.

    

During gout attacks, uric acid deposits may build up in cartilage, tendons and other soft tissues. They may also form lumps called tophi under the skin and may accumulate in the kidneys forming kidney stones.

 

Causes

Gout is caused by an excess of uric acid in the blood (hyperuricemia). Uric acid is produced in the body during the breakdown of purines – chemical compounds that are found in high amounts in certain foods such as meat, poultry and seafood.

Normally, uric acid is dissolved in the blood and is excreted from the body in urine via the kidneys. If too much uric acid is produced, or not enough is excreted, it can build up and form needle-like crystals that trigger inflammation and pain in the joints and surrounding tissue.

 

Diet plays a big role in high uric acid levels. A diet rich in purines often results in elevated levels of uric acid. Consuming too much alcohol, particularly beer, can also cause uric acid levels to rise.

Risk Factors for Gout

There are a number of factors that can increase the likelihood of hyperuricemia, and therefore gout:

  • Age and Gender – Men produce more uric acid than women, though women’s levels of uric acid approach those of men after menopause
  • Genetics – A family history of gout increases the likelihood of the condition developing
  • Lifestyle Choices – alcohol consumption interferes with the removal of uric acid from the body. Eating a high-purine diet also increases the amount of uric acid in the body

         Foods high in purines include:

   

  • Medications – certain medications can increase the levels of uric acid in the body; these include some diuretics and drugs containing salicylate
  • Weight – being overweight increases the risk of gout as there is more turnover of body tissue, which means more production of uric acid as a metabolic waste product
  • Recent Trauma or Surgery – increases risk
  • Other Health Problems – renal insufficiency and other kidney problems can reduce the body’s ability to efficiently remove waste products, leading to elevated uric acid levels

Location

Gout frequently affects the large joint of the big toe, but it can also affect:

  • Ankles
  • Knees
  • Elbows
  • Wrists
  • Fingers

  

Stages of Gout

  1. Asymptomatic Hyperuricemia

It is possible for a person to have hyperuricemia (elevated uric acid levels) without any outward symptoms. At this stage, treatment is not required, though urate crystals are being deposited in tissue and causing slight damage.

  1. Acute Gout

This stage occurs when the urate crystals that have been deposited suddenly cause acute inflammation and intense pain. This sudden attack is referred to as a “flare” and will normally subside within 3-10 days. Flares can sometimes be triggered by stressful events, alcohol and drugs, as well as cold weather.

  1. Interval or Intercritical Gout

This stage is the period in between attacks of acute gout. Subsequent flares may not occur for months or years, though if not treated, over time, they can last longer and occur more frequently. During this interval, further urate crystals are being deposited in tissue.

  1. Chronic Tophaceous Gout

Chronic tophaceous gout is the final stage and the most debilitating form of gout. Permanent damage may have occurred in the joints and the kidneys. The patient can suffer from chronic arthritis and develop tophi – big lumps of urate crystals – in cooler areas of the body such as the joints of the fingers.

It takes a long time without treatment to reach the stage of chronic tophaceous gout – around 10 years. It is very unlikely that a patient receiving proper treatment would progress to this stage. 

 

Prevention

There are many lifestyle and dietary guidelines that can be followed to protect against future flares or prevent gout from occurring in the first instance:

  • Maintain a high fluid intake (2-4 liters a day)
  • Avoid alcohol
  • Maintain a healthy body weight
  • Eat a balanced diet

     

  • Limit fish, meat and poultry intake

Non-Surgical Treatments

The majority of gout cases are treated with medication. Medication can be used to treat the symptoms of gout attacks, prevent future flares and reduce the risk of gout complications such as kidney stones and the development of tophi.

Commonly used medications include:

  • Allopurinol to reduce the production of uric acid
  • Uricase is an enzyme that converts uric acid to allantoin. Allantoin is much more soluble than uric acid, and passes harmlessly from the body
  • Probenecid to remove uric acid from the body
  • Nonsteroidal anti-inflammatory drugs (NSAIDs), colchicine, or corticosteroids to reduce inflammation and pain

      

Surgical Treatments

  • Syringe to remove fluid from the inflamed joint