Gout: diagnosis and medical treatment

2021-07-19 11:30 PM

Gout is a metabolic disorder of purine nuclei, with the main feature being hyperuricemia. Arthritis in gout is caused by the deposition of monosodium urate crystals in joint fluid or tissues.

The stages of Gout progression: High uric acid, acute gout, intercritical gout,chronic gout.

Four stages of Gout progression.

Gout is common in middle-aged men, peaking at 50 years of age, but the incidence increases gradually in both men and women in the older age groups.

Gout is a metabolic disorder of purine nuclei, with the main feature being hyperuricemia. Arthritis in gout is caused by the deposition of monosodium urate crystals in joint fluid or tissues.

There are two types of primary gout and secondary gout.

Gout is common in middle-aged men, peaking at 50 years of age, but the incidence increases gradually in both men and women in the older age groups.

The typical acute gout

Attacks are often spontaneous, with sudden onset at night.

Common in joints in the lower extremities such as the big toe, knee, and foot.

Severe pain, burning joints. Joint mosaic is swollen, hot, red, painful.

Good response to colchicine, inflammatory symptoms completely relieved after 48 hours.

Acute gout attacks may resolve on their own within 1-2 weeks even without treatment.

Chronic gout

Between exacerbations, damaged joints are mostly asymptomatic, but urate crystals continue to deposit. After many times, there is an acute gout attack with increasing severity. Finally, after many years with acute gout attacks, the disease progressed to chronic tophi. At this time, the clinical, biochemical, and radiological manifestations are manifestations of urate accumulation in tissues, demonstrating the chronic process.

Chronic gout has manifestations such as tophi (on the surface of joints, articular edges, ear cartilage, ...), chronic joint disease with joint damage on X-ray, gouty kidney disease (urinary stones, kidney stones, etc.) kidney failure, ultrasound may show kidney stones).

Blood uric acid test

Hyperuricemia: men over 420pmol/l (70mg/l), women over 360pmol/l (60mg/l).

If the uric acid in the blood is normal, it does not rule out the diagnosis, and vice versa, if the uric acid is high, there are no clinical symptoms nor does the diagnosis of gout. Uric acid should not be used as a standard for definitive diagnosis, but only for the purpose of supporting diagnosis and monitoring in treatment.

24-hour urine uric acid quantification

For therapeutic purposes: to determine whether the excretion of urate is increased (more than 600 mg/24 hours) or relative decreased (less than 600 mg/24 hours). If in the state of increased urinary uric acid excretion, do not use uric acid-lowering drugs with increased excretion mechanism (probenecid).

Joint fluid testing (in the case of knee arthritis, effusion is often present)

Inflammatory joint fluid, rich in cells (over 50,000 leukocytes/mm3), mainly polymorphonuclear leukocytes (non-degenerative).

If urate crystals are visible, confirm the diagnosis of a gout attack. These are double-headed, variable numbers of pointed crystals, located inside or outside of leukocytes. Under a polarizing microscope, this crystal is clearly polarized.

Kidney function test

It is necessary to examine renal function systematically: urea, blood creatinine, 24-hour proteinuria, urinalysis, urinary pH, renal ultrasound.

Blood tests for inflammation

Elevated erythrocyte sedimentation rate.

Leukocytosis increased, in which neutrophils increased.

C-reactive protein is elevated.

Joint X-ray

In the acute gout phase, joint radiographs are generally normal.

Testing for other comorbidities

Blood lipids and blood sugar should be investigated because these metabolic disorders are often combined.

Bennett and Wood's Criterion (1968)

Gout is definitively diagnosed when urate crystals are found in joint fluid or tophi.

Or urate crystals are found in synovial fluid or in tophi.

Or at least 2 of the following criteria:

History or current of at least 2 episodes of painful swelling of a joint WITH sudden onset, severe pain, and complete resolution within two weeks.

History or presence of painful swelling of the big toe joint with the above characteristics.

There are tophi.

Good response to colchicine (inflammation, pain relief in 48 hours) in history or present.

Diagnosis is confirmed when criteria 1 or 2 of criteria 2 are present.

Differential diagnosis

Infective arthritis: damage to one joint, the patient may have a fever, sometimes accompanied by chills.

There is usually an access route and an infection, and there is no acute gout attack. Joint fluid may contain degenerating polymorphonuclear leukocytes. Arthroscopy to detect infectious arthritis that may be associated with gout.

Reactive arthritis: there is a history of the previous infection of other organs (urinary, genitourinary), no acute gout attack.

Rheumatoid arthritis: usually in women, the pain is not hot, red, and there is no acute gout attack.

Pseudo-gout arthritis is an inflammatory condition of the joints, soft tissue adjacent to the joints caused by calcium phosphate crystals, cholesterol crystals,... Clinical manifestations of acute arthritis are relatively similar to acute gout attacks. However, it is common in the elderly, combined with many degenerative joint conditions. No tophi. The test finds calcium crystals, (not urate crystals) in the joint fluid or the site of the injury.

Cellulitis is an inflammatory condition of the skin and subcutaneous tissues that can be periarticular or extra-articular. Common in the lower extremities, there are favorable factors such as skin scratches, previous blistering.

Treatment purpose

Treatment of acute gout attacks and prevention of recurrence of acute gout attacks.

Prophylactic treatment of complications due to gout.

Treatment goals

Blood uric acid is less than 360pmol/l (60mg/l) with gout without tophi and less than 320pmol/l (50mg/l) when gout has tophi.

Treatment of acute gout 

Anti-inflammatory drugs

Colchicine: 1 mg tablet.

Colchicine has a role in the anti-inflammatory treatment of acute gout attacks, a diagnostic test for gout, and a role in the prevention of acute gout attacks.

Previously, starting dose: 3mg/24 hours, divided into 3 times, for 2 days; next: 2mg/24 hours, in 2 divided doses, for the next 2 days; then: 1mg/24 hours, maintain for 15 days, sometimes 1-2 months to avoid recurrence. Such a starting dose is also used only as a diagnostic test for gout. Currently, there are many views that do not use high-dose colchicine but divide the dose of 0.6mg/6 hours or 1-2 tablets/day and/or combine it with another non-steroidal anti-inflammatory drug from the beginning to limit Gastrointestinal side effects of colchicine.

Non-steroidal anti-inflammatory drugs

Choose one of the following drugs (note absolutely do not combine drugs in the group because they do not increase the treatment effect but have many side effects):

Diclofenac (Voltaren) 50mg x 2 tablets/day divided into 2 or 75mg x 1 tablet/day after a full meal. 75mg/day intramuscular injection can be used for the first 2-4 days when the patient is in great pain, then switch to oral.

Meloxicam (Mobic) tablet 7.5mg x 2 tablets/day after eating or as an intramuscular injection 15mg/day x 2-4 days if the patient has a lot of pain, then switch to oral route.

Piroxicam (Felden) 20mg tablets or ampoules, take 1 tablet per day orally after meals or intramuscularly 1 ampoule in the first 2-4 days when the patient has a lot of pain, then switch to oral.

Celecoxib (Celebrex) 200mg tablets, dose 1 to 2 tablets / day after a full meal. Should not be used in patients with a history of cardiovascular disease and with greater caution in the elderly.

Corticosteroids: are often indicated for patients with contraindications to colchicine, CVKS or treatment but are not effective. Corticosteroids can be administered intra-articularly.

Analgesic

Choose one of the drugs from the World Health Organization analgesic ladder acetaminophen (paracetamol, Efferalgan), Efferalgan codeine, morphine. For example, use paracetamol 0.5g tablets with a dose of 1-3g/day. Depending on the pain, adjust the dose accordingly.

Urine alkalinization

Make sure the water can be filtered well by the kidneys so that the amount of uric acid in the urine does not exceed 400mg/l.

Alkalize the urine with alkaline mineral water or 14% alkaline water to ensure 2 liters of water per day.

Diet, living

Principles of food hygiene for gout patients:

Reduced protein diet (meat no more than 150g/day), avoid foods high in purines, reduce fat.

Reach a bodyweight at a physiological level, eat fewer calories if obese.

Drink plenty of water, especially alkaline mineral water.

Patients should:

Drink plenty of water daily, preferably alkaline mineral water.

Eat lots of green vegetables, artichokes, lettuce, carrots, cabbage, cucumbers, melons, green beans, potatoes, tomatoes, fresh mushrooms, bamboo shoots.

Can eat eggs, milk, and products, non-fermented white cheese, lean fish.

It is necessary to avoid taking certain drugs that can increase blood uric acid: diuretics, corticosteroids, these drugs can reduce swelling and pain in the joints quickly, but in the long run, they will make the disease worse and some other drugs such as: : aspirin, anti-tuberculosis drugs.

Abstain from: alcohol, tea, viscera, dog meat, goat, seafood,...

Treatment of chronic gout

The purpose is to avoid acute gout attacks, to avoid damage to organs. Usually must lower blood uric acid below 60mg/l (360μmol/l). To achieve the goal, it is necessary to follow a good diet and medication regimen.

Diet

Adhere to the diet and alkalinize the urine as with acute gout attacks and must be maintained continuously on a daily basis.

Anti-inflammatory drugs

Colchicine: for the purpose of avoiding recurrent acute gout attacks. Can be used for 3 consecutive months or maintained for an additional month from the date of the end of arthritis. The daily dose is 1 tablet of colchicine 1mg, taken before going to bed. Non-steroidal anti-inflammatory drugs: can be used in combination with colchicine or alone in acute gout attacks.

Drugs to reduce uric acid

Drugs that inhibit uric acid synthesis:

Maintain this group of drugs until blood uric acid reaches below 60mg/l (360 µmol/l), even 50mg/l (320 µmol/l) in case of chronic gout with tophi.

Usually used continuously for 1-2 months. Then, depending on the amount of uric acid in the blood, adjust the dose. There are cases that must be maintained for life if the patient does not adhere to a strict diet, blood uric acid does not return to normal.

Allopurinol: brand name zyloric tablets 100 - 300mg.

Indications: all cases of gout. However, allopurinol should not be used during an acute attack but should wait about a week, when the inflammation subsides, to start giving allopurinol to avoid the onset of an acute gout attack. If you are taking allopurinol and have an exacerbation, continue taking it. Dose: 200-400mg/24 hours.

Side effects: increased skin sensitivity (rash, papules, urticaria), anaphylaxis, vasculitis, hepatitis (rare).

Drugs that increase uric acid excretion: probenecid (500mg x 1-2 tablets/24 hours):

Mechanism: These drugs have the effect of increasing uric acid excretion through the kidneys and inhibiting tubular absorption, reducing blood uric acid, but increasing uric acid in urine.

Indications: cases of intolerance to drugs that inhibit uric acid synthesis.

Contraindications: gout with kidney damage or increased uric acid in the urine (over 600mg/24 hours).

Uric acid-reducing drugs (brand name Uricozyme):

Mechanism: This is a uricase enzyme that converts uric acid into allantoin, which is highly soluble and easily excreted from the body.

Indications: cases of acute hyperuricemia in blood diseases. Must be used in the hospital.

Generally very rarely used.

Treatment of chronic gout with complications

Renal failure: depending on the degree of kidney failure

Renal failure grade I and II, short-term treatment of anti-inflammatory drugs with oral corticosteroids and then stop, uric acid-lowering drugs with low-dose allopurinol 100-300mg daily or every other day.

Grade III or IV renal failure with the indication for dialysis.

Tophi

Surgery to remove tophi: very limited indications, only when the tophi are broken, leak fluid, and are too big to affect the movement function of the joints.

Broken tophi infection: daily dressing changes, wound removal, and systemic antibiotics are required. In general, ulcers take a long time to heal.

Prevention

Follow a healthy lifestyle and rest.

Follow a good diet, avoid drinking a lot of alcohol, avoid gaining weight and obesity.

Detecting acute gout attacks early to use drugs and make timely lifestyle adjustments to avoid becoming chronic gout and complications due to gout.

Related articles:

- Everything you need to know about Gout.

- Doctors usually diagnose gout based on your symptoms and the appearance of the affected joint. 

- Medications for Gout.