⁨أسئلة الثالثة روماتولوجي حورس ⁩

Gout

• Gout is a crystal-induced arthropathy
• Gout involves disorders of purine metabolism
• Serum uric acid elevation (hyperuricemia) is present in gout
• Urate deposition occurs in articular and extra-articular tissue

Classification of Gout

• There are two classifications, primary and secondary gout
• Primary gout accounts for 90% of cases
• Primary gout is caused by disorders of purine metabolism
• Primary gout is caused by abnormal excretion of uric acid
• Secondary gout is caused by impaired uric acid excretion
• Secondary gout can be caused by chronic renal diseases
• Thiazide diuretics and low-dose aspirin can also cause secondary gout
• Hypertension causes secondary gout
• Lead toxicity causes secondary gout
• Hyperparathyroidism causes secondary gout
• Hypothyroidism can cause secondary gout
• Increased lactic acid production, alcohol consumption, and starvation cause secondary gout
• Glucose-6-phosphatase deficiency causes secondary gout
• Increased uric acid production leads to secondary gout
• Myeloproliferative disorders like polycythemia vera can cause secondary gout
• Lymphoproliferative disorders like leukemia can cause secondary gout
• Severe psoriasis cases can cause secondary gout

Clinical Picture of Gout

• Gout can manifest as acute gouty arthritis, inter-critical gout, or chronic gout
• Typical acute attacks occur in 95% of cases
• Rapid onset of acute severe pain that peaks within hours is typical
• Patients usually cannot bear weight or have the joint touched
• The skin around the affected joint may be red and peel
• Some patients have a slight fever and chills
• The most commonly affected joints are the first metatarsophalangeal joint (1st MTPj)
• The dorsum of the foot and knee are also commonly affected
• Joints of the upper limb are rarely affected

Inter-critical Gout

• Asymptomatic intervals occur between acute gout attacks
• Some patients never have a second attack

Chronic Gout

• With repeated acute attacks, the interval between attacks shortens
• Joints become permanently mildly swollen and deformed, with mild to moderate persistent pain
• Recurrent acute attacks may lead to progressive joint damage, deformity, and pain
• Chronic tophaceous gout involves large monosodium urate (MSU) crystal deposits that form firm nodules (tophi)
• Tophi are usually found on extensor surfaces of fingers, hands, and elbows
• Tophi are usually found on Achilles tendon and ears

Investigations for Gout

• Synovial fluid analysis, serum uric acid levels, blood tests, and radiologic features
• Synovial fluid is inflammatory with a predominance of neutrophils
• Synovial fluid is examined under a polarized light microscope for urate crystals, which are diagnostic

Serum Uric Acid

• Elevated serum uric acid is not diagnostic
• Serum uric acid may be normal in 30% of patients during an acute attack
• A high level alone is not diagnostic of gout
• Asymptomatic hyperuricemia may be observed

Blood Tests

• Leukocytosis can be detected
• Elevated erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) levels vary with the severity of gout

Radiologic Features

• Soft tissue swelling occurs around the affected joint during an acute attack
• In chronic gout, tophi and punched-out erosions with sclerotic margins and overhanging edges may be seen

Radiologic Observations

• Gout can involve the first metatarsophalangeal joint (1st MTPj)
• Peri-articular swelling is common
• Punched-out erosions are located away from the articular surface with an overhanging lip appearance
• Large tophaceous deposits may be present

Treatment for Gout

• Acute attacks and long-term management are crucial
• Nonsteroidal anti-inflammatory drugs (NSAIDs) are used in maximum doses for acute attacks
• Colchicine is administered at 0.5 mg every 3 hours for 12 hours for acute attacks
• Systemic steroids are for resistant cases
• Effusion in large joints is treated with aspiration and corticosteroid injection
• Long-term treatment is considered once the acute attack subsides

Long Term Gout Management

• Patient education
• Diet modification
• Colchicine
• Allopurinol
• Febuxostat
• Uricosuric drugs
• Joint management
• Prevention of renal stones

Patient education

• Patients should maintain an ideal body weight
• Patients should ingest at least 2 liters of fluids per day to prevent renal stones
• Avoid low-dose aspirin

Dietary Changes

• High-purine foods like meat and seafood should be avoided
• Intake of low-fat dairy products and vegetable proteins should be encouraged

Colchicine Dosage

• 0.5-1 mg/day
• Colchicine can be used to prevent gout flares

Allopurinol

• Allopurinol inhibits xanthine oxidase enzyme, diverting purine breakdown to more soluble xanthines
• It is administered at 100-300 mg/day
• Side effects include rash, vasculitis, and agranulocytosis
• Contraindicated in acute gout
• Low-dose NSAIDs or colchicine should be administered concurrently for at least 4 months

Febuxostat

• Selective inhibitor of xanthine oxidase enzyme, diverting purine breakdown to xanthines
• It does not inhibit other enzymes involved in purine or pyrimidine synthesis and metabolism
• Administered at 40-80 mg/day
• Has fewer side effects than allopurinol
• Arthralgia, chest pain, and dark urine are side effects
• Superior to allopurinol in mild and moderate renal dysfunction
• Contraindicated in acute gout

Uricosuric drugs

• Examples include probenecid and sulfinpyrazone
• Side effects include occasional rash or hepatitis
• Contraindicated in acute gout
• Low-dose NSAIDs or colchicine should be administered concurrently for at least 4 months

Joint management

• Joint aspiration can be performed for joint effusion
• Intra-articular corticosteroid injections can be administered to patients with persistent synovitis

Prevention of Renal stones

• Alkalinization of urine
• Maintain urine pH at 6
• Use sodium or potassium citrate or acetazolamide 500 mg at bedtime
• Drink an adequate volume of fluid to produce at least 2 liters of urine daily