Gout
From Wikipedia, the free encyclopedia.
Gout (also called gouty arthritis, Greek name: podagra, from pod - foot and agra - trap) is a form of arthritis caused by the accumulation of uric acid crystals in joints. It is an intensely painful disease, which in most cases affects only one joint (monoarthritis), most commonly the big toe.
Contents |
Signs and symptoms
The classic picture is of excruciating and sudden pain, swelling, redness, warmness and stiffness in the joint. Low-grade fever may also be present. The patient usually suffers from two sources of pain. The crystals inside the joint cause intense pain whenever the affected area is moved. The inflammation of the tissues around the joint also causes the skin to be swollen, tender and sore even if it is slightly touched. For example, a blanket draping over the affected area would cause extreme pain.
Gout usually attacks the big toe (approximately 75% of first attacks), however it can also affect other joints such as the ankle, heel, instep, knee, wrist, elbow, fingers, and spine. In some cases the condition may appear in the joints of the small toes which have become immobile due to impact injury earlier in life and there is poor blood circulation.
Patients with longstanding hyperuricemia (see below) can have uric acid crystal deposits called tophi (singular: tophus) in other tissues e.g. the helix of the ear. Uric acid stones can form as one kind of kidney stones in some occasions.
Diagnosis
The diagnosis is generally made on a clinical basis, although tests are required to confirm the disease.
Hyperuricemia is a common feature; however, urate levels are not always raised (Sturrock 2000). Hyperuricemia is defined as a plasma urate (uric acid) level greater than 420 μmol/L (7.0 mg/dL) in males ( the level is around 380 μmol/L in females ); despite the above, high uric acid level does not necessarily mean a person will develop gout. Additionally, urate falls to within the normal range in up to 2/3 of cases (Siva et al 2003). If gout is suspected, the serum urate should be repeated once the attack has subsided.Other blood tests commonly performed are full blood count, electrolytes, renal function and erythrocyte sedimentation rate (ESR). This serves mainly to exclude other causes of arthritis, most notably septic arthritis.
A definitive diagnosis of gout is from light microscopy of joint fluid aspirated from the joint (this test may be difficult to perform) to demonstrate intracellular monosodium urate crystals in synovial fluid polymorphonuclear leukocytes. The urate crystal is identified by strong negative birefringence under polarised microscopy, and their needle like morphology. A trained observer does better in distinguishing them from other crystals.
Pathogenesis
Although the exact cause of gout is not known, it is thought to be linked to defects in purine metabolism. Purine is an organic compound commonly found in the body and is metabolized by the body into uric acid. People with primary gout have either an increased production of uric acid or an impaired excretion of uric acid, or a combination of both.
There are also different racial propensities to develop gout. The prevalence of gout is high among the peoples of the Pacific Islands, and the Maori of New Zealand, but paradoxically rare in the Australian aborigine despite the latter's higher mean concentration of serum uric acid (Roberts-Thomson 1999).
Hyperuricemia is considered an aspect of the metabolic syndrome, although its prominence has been reduced in recent classifications. This explains the increased incidence of gout in obesity.
Gout can also develop as co-morbidity of other diseases, including obesity, diabetes, hypertension, renal disorders, and hemolytic anemia or due to use of diuretics, such as thiazide. This form of gout is often called secondary gout, and is commonly found in the elderly population.
Stages of Gout
Gout has four distinct stages: asymptomatic, acute, intercritical, and chronic.
In the first (asymptomatic) stage, plasma uric acid level increases, but there are no symptoms. The first attack of gout marks the second or acute stage. Mild attacks usually go away quickly, whereas severe attacks can last days or even weeks. After the initial attack, the person enters the intercritical stage or symptom-free interval that may last months or even years. Most gout patients have their second attack within 6 months to 2 years from their initial episode.
In the last or chronic stage, gout attacks become frequent and become polyarticular (affecting multiple joints at one time). Large tophi can also be found in many joints. In advanced cases of chronic gout, kidney damage, hypertension, and urolithiasis (kidney stone) can also develop.
Treatment
Attacks
Acutely, first line treatment should be pain relief. Once the diagnosis has been confirmed, the drugs of choice are indomethacin, other nonsteroidal anti-inflammatory drugs (NSAIDs), or intraarticular glucocorticoids, administered via a joint injection.
Colchicine was previously the drug of choice in acute attacks of gout. It impairs the motility of granulocytes and can prevent the inflammatory phenomena that initiate an attack of gout. Colchicine should be taken within the first 12 hours of the attack and usually relieves the pain within 48 hours. Its main side-effects (gastrointestinal upset) can complicate its use. NSAIDs are the preferred form of analgesia for patients with gout.
Before medical help is available, some over the counter medication can provide temporary relief to the pain and swelling. NSAIDs such as ibuprofen can reduce the pain and inflammation slightly. Preparation H hemorrhoidal ointment can be applied to the swollen skin to reduce the swelling temporarily. Professional medical care is needed for long term management of gout.
Prevention
Long term treatment (in frequent attacks) is antihyperuricemic therapy. Dietary change can make a small contribution to lowering the plasma urate level if a diet low in purines is maintained, because the body metabolizes purines into uric acid. The mainstay of this approach, however, is the drug allopurinol, a xanthine oxidase inhibitor, which directly reduces the production of uric acid. However, allopurinol treatment should not be initiated during an attack of gout, as it can then worsen the attack. If a patient is on allopurinol during an attack, it should be continued.
The decision to use allopurinol is often a lifelong one. Patients have been known to relapse into acute arthritic gout when they stop taking their allopurinol, as the changing of their serum urate levels alone seems to cause crystal precipitation.
Probenecid, a uricosuric drug that promotes the excretion of uric acid in urine, is also commonly prescribed - often in conjunction with colchicine. Interestingly, the drug fenofibrate (which is used in treating hyperlipidemia) also exerts beneficial uricosuric effect (Bardin 2003).
Allopurinol and ucosoric agents are contraindicated in patients with kidney stones and other renal conditions.
As arterial hypertension quite often coexists with gout treating it with losartan, an AT receptor antagonist, might have an additional beneficial effect on uric acid plasma levels. This way losartan can for instance offset the negative side-effect of thiazides (a group of diuretics used for high blood pressure) on uric acid metabolism in patients with gout.
Surgery
For extreme cases of gout, surgery may be necessary to remove large tophi and correct joint deformity.
Diet
Low purine diet :
- To lower uric acid:
- cherries have been shown to reduce uric acid
- strawberries or blueberries (and other dark red/blue berries) are also reputed to be beneficial
- celery extracts (celery or celery seed either in capsule form or as a tea) is believed by many to reduce uric acid levels.
- limit meats to one serving a day
- Food to avoid:
- foods high in purines, that is, high in DNA
- diet sodas (these act as diuretics in many people, causing uric acid to concentrate in the blood which can then easily precipitate)
- To avoid dehydration:
- Folklore has it that Joe-Pye weed flushes uric acid quickly, but continued use can damage the liver or kidneys
- Another folk remedy is the use of oenomel, a drink with honey and unfermented grape juice.
- Moderate intake of purine-rich vegetables is not associated with increased gout (Choi et al 2004)
Suggestions for Pain Relief
Improved blood circulation in the immediate area of an affected immobile joint can be encouraged with a warm bath. This assists in the relief of swelling and reduction in Uric crystallisation. Ensure area is dry before putting on clothes.
Additional Observations
Due to swelling around affected joint for prolonged periods, shedding of skin may occur. This is particularly evident when small toes are affected and may promote fungal infection in the web region if dampness occurs. Pure Tea Tree Oil mixed with Aloe Vera Gel can control secondary fungal infection. Treat in a similar fashion to Athlete's foot.
History
Gout was traditionally viewed as a disease of the decadent and indolent, because the foods which contribute to its development were only available in quantity to the wealthy. The stereotypical victim was a lazy, obese middle-aged man who habitually overindulged in rich foods and alcohol, with port consumption often cited as a specific cause.
Perhaps due to the traditional relationship between wealth and literacy, gout is one of the most commonly-reported maladies in history.
The Roman gladiatorial surgeon Galen described gout as a discharge of the four humors of the body in unbalanced amounts into the joints. The Latin term for a drop, as a drop of discharge, is gutta -- the term gout descends from this word.
Famous people who had gout
One of the most famous sufferers of gout was Henry VIII. Others include Khubilai Khan, Nostradamus, John Milton, Isaac Newton, Samuel Johnson, Charles V, Pablo Neruda, Alfred Lord Tennyson, George IV,John Hancock, Thomas Jefferson, William Pitt, 1st Earl of Chatham William B. Finneran, Kirk Reuter and Benjamin Franklin.
The Roman poet Ennius wrote numquam poetor nisi podager — "I only write poetry when I suffer from gout". He used the enforced idleness caused by his arthritis to compose poetry.
Gout in fiction
In an episode of King of the Hill, Bobby Hill develops gout in the big toe as a result of eating chopped liver on a daily basis.
In an episode of Lost In Space, Will Robinson encounters Hamish Rhu-Glamis, a Scotsman executed in 1497, but who was suffering gout at the time of his death. Will's mother Maureen attempts to treat the gout when Hamish is made living again by passage through a space warp.
In George Eliot's Middlemarch, Tertius Lydgate publishes a book on gout.
See also
Pseudogout is very similar disease, but caused by deposition of calcium pyrophosphate, not uric acid.
References
- Bardin, T: Fenofibrate and losartan. Annals of the Rheumatic Diseases 2003;62:497-498. Full text. PMID 12759281.
- Choi HK, Atkinson K, Karlson EW, Willett W, Curhan G. Purine-rich foods, dairy and protein intake, and the risk of gout in men. N Engl J Med 2004;350:1093-103. PMID 15014182.
- Roberts-Thomson RA, Roberts-Thomson PJ. Rheumatic disease and the Australian aborigine. Ann Rheum Dis 1999;58:266-70. Fulltext. PMID: 10225809
- Siva C, Velazquez C, Mody A, Brasington R. Diagnosing acute monoarthritis in adults: a practical approach for the family physician. Am Fam Physician 2003;68:83-90. PMID 12887114.
- Sturrock RD. Gout. Easy to misdiagnose. BMJ 2000;320:132-3. Fulltext. PMID 10634714.
- Kumar and Clark, eds. Clinical Medicine, 4th Edition 1998.
- Harrison's principles of internal medicine.
