Gout

Gout is a form of arthritis caused by hyperuricemia. Hyperuricemia is defined as a plasma urate (uric acid) level greater than 420 μmol/L (7.0 mg/dL); hyperuricemia is a cardinal feature of gout and necessary for gout although a high uric acid level does not necessarily mean a person will develop gout.

Etiology

People with gout have either an increased production of uric acid or an impaired excretion of uric acid, or a combination of the two.

High uric acid levels are associated with age, obesity, type IV hyperlipidaemia, diabetes mellitus, ischaemic heart disease and hypertension. Sometimes, a person can inherit a genetic predisposition from their families.

Symptoms and signs

The classical picture is of excruciating pain of sudden onset in only one joint, usually the big toe (75% of first attacks are the first metatarsal-phalangeal joint).

Diagnosis

A definitive diagnosis of gout is from 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.

Serum urate levels are usually raised. Serum urea and creatinine may be raised if there is any renal impairment.

Treatment

Acutely, first line treatment should be pain relief. Once the diagnosis has been confirmed, the drugs of choice are colchicine, nonsteroidal anti-inflammatory drugs (NSAIDs), or intraarticular glucocorticoids.

Long term treatment is antihyperuricemic therapy. Dietary change can make a small contribution to lowering the plasma urate level if a diet low in purines is considered. The mainstay of this approach, however, is the drug allopurinol, a xanthine oxidase inhibitor, which directly reduces the production and increases urinary excretion of uric acid.

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 seems to cause crystal precipitation.

Low Purine Diet:

  • cherries have been shown to reduce uric acid

  • strawberries are also reputed to be beneficial

  • avoid foods high in purines, that is from protein sources

  • limit meats to one serving a day

Never eat:

  • sweetbreads, kidneys, liver, brains, or other offal meats

  • sardines

  • anchovies

  • meat extracts, consomm?, and gravies

Use sparingly:

  • asparagus, beans, lentils, peas, mushrooms, cauliflower, spinach, rhubarb

Avoid dehydration:

  • Drink plenty of liquids, especially water, to dilute and assist excretion of urates;

  • Use diuretic foods or medicines like aspirin, vitamin C, tea and alcohol sparingly.

previous.gif (72x17 -- 347 bytes) next.gif (72x17 -- 277 bytes)

Are you a Doctor, Pharmacist, PA or a Nurse?

Join the Doctors Lounge online medical community

  • Editorial activities: Publish, peer review, edit online articles.

  • Ask a Doctor Teams: Respond to patient questions and discuss challenging presentations with other members.

Doctors Lounge Membership Application

Tools & Services: Follow DoctorsLounge on Twitter Follow us on Twitter | RSS News | Newsletter | Contact us