Gout is defined as inflammation of the joint caused by increased uric acid in the blood and formation of monosodium urate (also called uric acid) crystals in the joints.
High level of uric acid in the blood is called hyperuricaemia.
Gout usually causes a type of arthritis called Monoarthritis where one joint is involved but later causes polyarthritis.
It is 5 times more common in men than women. For women, risk of gout increases after menopause.
Middle aged men are common victims of gout.
How Gout Occurs
Gout Arthritis is caused by excess uric acid in the blood which some of it end up being deposited in the joints.
The acid in the joints induces inflammatory response if the affected joint, causing acute gout attack.
Causes of Hyperuricemia
Uric acid normally is present in the blood in small amounts, it is eliminated by the kidneys when there is increased production.
Causes of high uric acid level are grouped into factors that increase production and factors that cause reduced excretion.
Breakdown of DNA in certain foods (listed shortly) is known to increase uric acid. These foods are called purine rich foods.
Increased uric acid production causes are:
- Excess alcohol intake including non-alcoholic beer which is rich in guanosine, a purine
- Eating lot purine-rich foods like red meat, liver, asparagus, mushrooms, and sardines
- Starvation
- Dehydration
- Genetic factors are also known to play a role in risk of gout
- Certain drugs like warfarin and other medical conditions such as Tumor Lysis Syndrome
Reduced Uric Acid excretion by kidneys, caused by:
- Chronic Kidney Disease
- Hypertension
- Drugs like Thiazide diuretics, Ethambutol, Pyrazinamide and low dose aspirin
- Hypothyroidism
Infections and trauma are also known to induce gout.
Some major surgeries of the joints can cause gout.
Signs and Symptoms
Gout usually presents as a flare or acute attack on one joint.
There is severe pain, swelling, and Inflammation of a single joint, usually the metatarsophalyngeal joint of the big toe.
This can be mistaken for Septic arthritis (see Arthritis) because there is only one joint involved.
Swelling may spread beyond the joint and be mistaken with cellulitis.
After some time, more joints are involved. Common joints involved are foot, ankle, elbow and fingers joints.
In elderly people and women, gout may start as polyarthritis.
Diagnosis and Lab tests for Gout
When a person has signs suggestive of gout, the following lab tests are done to confirm or exclude gout:
- Blood uric acid level: A high value indicates hyperuricaemia
- CRP and ESR: These are inflammatory markers which are also usually elevated
- X-Ray: it may show well defined ‘punch out’ erosions in the late stages of the disease
- FBC, and U&E: A raised white cell count in FBC may indicate infection instead of gout. Renal function is also important to know as we know impaired renal function leads to gout.
- Joint Aspiration and analysis of its fluid reveals long needle shaped crystals. This is usually not done in practice.
Treatment of Gout
There are Two main important steps of treating gout.
There’s treatment of acute flare up/attack, and lowering of uric acid.
Acute Gout Flare treatment
In the initial stage of gout, the aim is to reduce pain and inflammation.
Rest is important at this stage.
It is followed by use of NSAIDs or colchicine as follows:
Ibuprofen 400mg oral 8 hourly with meals OR,
Colchicine 1mg immediately, then 0.5mg 12 hourly.
Colchicine is used if NSAIDs like Ibuprofen or Diclofenac are not tolerated, like in people with Peptic Ulcer Disease.
Acid Lowering Treatment
As a long-term treatment uric acid is lowered with use of allopurinol.
Allopurinol is given 2 weeks after the attack has settled.
The common dose is 100mg daily, which may be increased based uric acid level in the blood.
Complications of Hyperuricemia
Hyperuricaemia complications come after a long time with gout or if it is undertreated.
- Tophaceous gout, defined as development of tophi or large whitish crystal deposits in the joints and under the skin
- Renal obstruction caused by urate renal stone formation
Prevention
Prevention of gout involves many factors which involves both the doctor and the patient with gout. These are:
- Drinking lot of fluids
- Avoid alcohol as it is associated with other health problems like Alcohol liver disease
- Avoid or use low dose of drugs that cause gout like thiazides and aspirin
- Weight loss in people with Obesity.
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