BASICS
Description
- Acute inflammatory arthritis with red, hot, swollen joints.
- Caused by deposition of monosodium urate (MSU) crystals.
- Commonly affects first metatarsophalangeal joint (podagra), foot, ankle, knee.
- Chronic disease can cause tophi, joint destruction, urate nephropathy, nephrolithiasis.
- Flares usually monoarticular; polyarticular flares can have systemic symptoms.
Epidemiology
- Prevalence 0.68% to 3.9% in adults.
- More common in males.
Etiology and Pathophysiology
- Four stages:
- Hyperuricemia (overproduction or decreased excretion).
- MSU crystal deposition triggered by local factors (cold, trauma, acidosis).
- Acute inflammatory response causing gout flare.
- Chronic gout with tophi and joint damage.
- Genetic association: HLA-B*5801 allele (esp. in Asians).
Risk Factors
- Age >40 years.
- High purine diet: alcohol (beer), red meat, seafood, sugary beverages.
- Metabolic syndrome, diabetes, obesity, hypertension.
- Medications: thiazide diuretics, loop diuretics, niacin, aspirin.
- Transplant recipients on calcineurin inhibitors.
- Tumor lysis syndrome.
Prevention
- Diet modification: avoid purine-rich foods and alcohol.
- Maintain hydration.
DIAGNOSIS
History
- Rapid onset severe joint pain, swelling, erythema.
- Joint intolerance to touch, often waking patients at night.
- Precipitating factors: infection, injury, dehydration, alcohol/purine intake.
- Chronic gout: tophi at joints, ears, olecranon, tendon.
Physical Exam
- Tender, swollen, warm joint(s).
- Tophi: firm nodules on joints, ears, olecranon, Achilles tendon.
Differential Diagnosis
- Septic arthritis
- Pseudogout (calcium pyrophosphate deposition disease)
- Cellulitis
- Osteoarthritis
- Rheumatoid arthritis
- Traumatic arthritis
- Hemarthrosis
Diagnostic Tests
- Synovial fluid analysis: negatively birefringent needle-shaped MSU crystals (pathognomonic).
- Uric acid levels (may be normal during attacks).
- Serum inflammatory markers (WBC, ESR, CRP) may be elevated.
- 24-hour urine uric acid in early onset or history of stones.
- Imaging:
- X-rays: periarticular erosions in chronic disease.
- Ultrasound: double contour sign, tophi.
- DECT: urate deposits.
TREATMENT
General Measures
- Supportive care: rest, ice, hydration.
Acute Attack
- Initiate treatment within 12-24 hours, continue 1-2 days after symptom resolution.
- NSAIDs: naproxen 500 mg BID, meloxicam 7.5-15 mg daily, indomethacin, diclofenac, ibuprofen.
- Corticosteroids: oral (15-35 mg prednisone daily for 5 days) or intra-articular.
- Colchicine: loading dose 1-1.2 mg, then 0.5-0.6 mg 1 hr later, then 0.5-0.6 mg q8h; max 6 mg/course.
- Combination therapy for severe attacks.
Chronic Management
- Urate-lowering therapy targeting serum uric acid <6 mg/dL.
- First line: allopurinol (start low, titrate up), febuxostat.
- Uricosurics: probenecid (avoid if CrCl <50 or history of stones).
- IL-1 inhibitors (anakinra, canakinumab) if contraindications/intolerance.
- Continue anti-inflammatory prophylaxis during initiation (low-dose colchicine or NSAIDs).
Additional Therapies
- Losartan and fenofibrate for uricosuric effects in hypertension or lipid disorders.
- Surgery for large tophi causing functional impairment or infection.
Complementary Medicine
- Vitamin C (>500 mg daily) may reduce serum uric acid.
ONGOING CARE
Follow-Up
- Monitor serum uric acid q2-5 weeks during titration.
- Periodic renal, liver, CBC tests.
- Reinforce lifestyle and dietary advice.
Diet
- Avoid organ meats, high fructose corn syrup, excessive alcohol.
- Limit red meat, shellfish, sweetened beverages.
- Encourage coffee, high-fiber foods, dairy, cherries.
- Weight loss in overweight patients.
Patient Education
- Flare-ups may increase during urate-lowering therapy initiation.
- Early treatment of acute flares improves outcomes.
- Adherence to lifestyle modifications is essential.
Prognosis
- Generally well-managed with appropriate treatment.
- Chronic gout can cause joint damage and nephropathy if untreated.
Complications
- Chronic arthritis and joint destruction.
- Uric acid nephropathy, kidney stones.
Clinical Pearls
- Podagra is the classic first presentation.
- MSU crystals on synovial fluid are diagnostic.
- Treat acute flares within 24 hours.
- Asymptomatic hyperuricemia does not require treatment.
References
- Abhishek A, Roddy E, Doherty M. Gout—a guide for the general and acute physicians. Clin Med (Lond). 2017;17(1):54-59.
- Rogenmoser S, Arnold MH. Chronic gout: Barriers to effective management. Aust J Gen Pract. 2018;47(6):351-356.
- Neogi T, Jansen TLTA, Dalbeth N, et al. 2015 Gout classification criteria: an American College of Rheumatology/European League Against Rheumatism collaborative initiative. Arthritis Rheumatol. 2015;67(10):2557-2568.
- daSilva MT, de Fátima Haueisen Sander Diniz M, Coelho CG, et al. Intake of selected foods and beverages and serum uric acid levels in adults: ELSA-Brasil (2008-2010). Public Health Nutr. 2020;23(3):506-514.
- Lamb KL, Lynn A, Russell J, et al. Effect of tart cherry juice on risk of gout attacks: protocol for a randomised controlled trial. BMJ Open. 2020;10(3):e035108.
- Choi HK, Atkinson K, Karlson EW, et al. Obesity, weight change, hypertension, diuretic use, and risk of gout in men: the health professionals follow-up study. Arch Intern Med. 2005;165(7):742-748.