Metabolic disorders

Gout

Last update: 14-12-2022

How else can it be called?

  • Hyperuricemia

  • Gouty arthritis

  • ICD-10: M10

What is gout?

Gout is a metabolic disorder characterized by a high level of uric acid in the blood that leads to crystal deposits in the joints, causing inflammation and pain, especially in the feet and legs.

It usually affects middle-aged men and postmenopausal women.

It is frequently related to other chronic diseases such as obesity, hypertension, hyperlipemia (high cholesterol and triglycerides in the blood) and diabetes. For that reason, their complications also appear in case of suffering gout (heart attack and stroke).

Another serious long-term complication that should be avoided is the kidney damage caused by uric acid stones.

What are the main causes of gout?

Uric acid is a product of the breakdown of purines, organic compounds present in some foods.

Not everyone with a high level of uric acid in the blood (hyperuricemia) develops gout. Only 20-30% will develop it and the causes are not still clear.

A high uric acid in the blood can be a consequence of:

  • The uric acid is not correctly excreted by the kidneys: due to hereditary or unknown causes
  • An increase in the uric acid production due to:
    • Excessive intake of food rich in purines: organ meats, seafood and red meat. (purine-rich vegetables are not known to be harmful or not)
    • Drinks with a high amount of fructose
    • Alcohol, especially the beer
    • Drugs: aspirin and diuretics such as hydrochlorothiazide
    • Drugs used after transplants

When there is too much uric acid in the blood it can build up and cause the formation of tiny sharp crystals in the joints, especially in the lower extremities (feet and legs).

These crystals lead to the inflammation and pain of the joints in what is called a gout flare.

Some of the crystals are also excreted into the urine and may produce kidney stones.

If the gout flares are frequent and the level of uric acid in the blood keeps on high, joint deformity in affected joints may appear and it is called tophi gouts.

How is the evolution of a gout flare?

A gout flare usually starts at night, with an intense pain followed by swelling and warmth in the affected joint. The pain increases for a period of 8 to 12 hours. The pain can be compared to stabbing a sharp and hot knife into the joint.

The initial flare frequently affects a single joint and in half of the cases the first joint involved is the metatarsophalangeal joint (located at the base of the big toe).

gout

Other joints frequently affected are the located in the foot, the ankle, the heel and the knee.

The wrist, the fingers and the elbows are often affected by gout flares later in the course of the disease.

The pain is intense and the person cannot bear any weight on the joint. Most of the patients find it difficult or impossible to walk.

The gout flare can be followed by fever, chills and malaise.

How can it be diagnosed?

The diagnosis of gout is usually made after a gout flare and it is confirmed if uric acid is high in the blood.

Anyway, the best way to diagnose gout is through a synovial fluid analysis to see if there are uric acid crystals. The synovial fluid is aspirated with a needle from the affected joint.

X-Ray and ultrasound of the joint often show a fluid accumulation in acute and chronic arthritis and tophi gouts in chronic arthritis.

What is the recommend treatment during a gout flare?

A gout flare or a gouty arthritis is treated with NSAIDs (non-steroidal anti-inflammatory drugs) and in many cases high doses are required.

Colchicine was used in high doses as antigout agent, but it usually causes diarrhea. Now, it is used in low doses with success.

Cold in the joint (cold packs or compresses) and rest are useful in case of gout flare.

Drugs that reduce the level of uric acid in the blood should never be used during a gout flare because they may be harmful.

Once the acute arthritis is under control, it is necessary to reduce the level of uric acid in the blood trough changes in lifestyle and medication.

Which are the general recommendations to treat the gout?

It is recommended to reduce exposure to everything that increases the uric acid in the blood:

  • Stress
  • Sugary drinks (they have a high amount of fructose)
  • Beer with and without alcohol
  • Alcohol in general
  • Red meat, seafood and organ meats
  • In radiology, the use of iodine-containing contrast
  • Thiazide diuretics such as hydrochlorothiazide, low-dose aspirin, and theophylline

If these factors are under control the uric acid in the blood may be reduced and no other additional measures are needed.

If the high uric acid in the blood (hyperuricemia) is secondary to other diseases, it is necessary to treat them. If diuretics have been prescribed for the treatment of another disease, it is advisable to replace them with other drugs with similar effects if it is possible.

A low intake of purines in the diet does not have many influences in the uric acid levels in the blood. For that reason, the diet does not need to be strict, especially if you are under medication.

The importance of an adequate diet lies in the fact that the increase in hyperuricemia is associated with the metabolic syndrome and increase in cardiovascular risks.

Therefore, if there is obesity, it is necessary to treat it and any other alteration of fats in the blood (cholesterol, triglycerides). In case of diabetes, it should also be treated.

If there are kidney stones, it is recommended to drink plenty of fluids, especially when the weather is hot, because the urine is more concentrated. Concentrated urine favors the formation of crystals that can lead to a stone in the kidney or the urinary tract.

The final decision to treat patients with medication to decrease uric acid levels in the blood is up to the doctor, depending on the particular circumstances of each case.

Which is the recommended treatment with medication?

If medication is needed to reduce the level of uric acid in the blood there are two types of drugs frequently used:

  • Anti-gout agents: They block the production of uric acid (allopurinol).
  • Uricosuric medication: They increase the excretion of uric acid in the urine (probenecid or sulfinpyrazone).

When using these drugs for the first time, it is a high risk to suffer a gout flare. For that reason, at the beginning of the treatment a low-dose of colchicine is also prescribed.

It is advisable to do a follow-up with uric acid blood tests periodically to adjust the dose of the medication.

Gout treatment is usually long-term and lifelong. This must be understood by the patients.

Sometimes, if some factors that contribute to a high uric acid in the blood are reversed (obesity, alcohol intake, follow a balanced diet), patients can reduce the doses of drugs to a minimal extent.

People with high uric acid in the blood, but no other complication, do not usually need medication.

Medically reviewed by Yolanda Patricia Gómez González Ph.D. on 14-12-2022

Bibliography

  • Rheumatology: Diagnosis & Therapeutics (2nd Ed). John J. Cush, Arthur Kavanaugh, C. Michael Stein. ISBN: 0-7817-5732-0. Pag. 332.
  • Harrison, Principles of Internal Medicine, 20th Edition (2018). Chapter 365 - Gout and Other Crystal-Associated Arthropathies. Pág. 6415. McGRAW-HILL ISBN: 978-1259644030.
  • Gout. American College of Rheumathology. Updated December 2021 by the American College of Rheumatology Committee on Communications and Marketing. Available on: https://www.rheumatology.org

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