Gout Workup and Diagnosis
The diagnosis and management of gout can be a challenge. Signs and symptoms of acute gout are very similar to other conditions such as septic arthritis, pseudogout, and fracture.
- Rapid development of pain, redness, swelling, tenderness and warmth in a single joint.
- Clinical features that need to be considered are location (distal lower extremity joint), onset, (especially evening), prior history of gout attacks, currently medication use, family history of gout, response to NSAIDs, dietary history, and male sex.
- Premenopausal women rarely develop acute gout. Estrogen has a protective effect on the excretion of uric acid.
- Hyperuricemia alone is insufficient to establish a diagnosis of gout because sUA measurements lack specificity and during acute flares sensitivity. Measurement of sUA should take place at least 2 weeks after a flare subsides.
- The gold standard for gout diagnosis is the presence of intracellular monosodium urate (MSU) crystals in synovial fluid or an aspirate of a tophus. However, this is unlikely to be practical for family physicians.
- A diagnosis of gout can be reasonably made by presumptive diagnosis based on multiple clinical features that are typical of gout. However, every effort should be made to eliminate other differential diagnoses including (a) septic arthritis, (b) pseudogout, (c) bone tumour, (d) fracture
- Bone tumour and fracture can be reasonably ruled out by a plain radiograph
- Septic arthritis or pseudogout require aspiration of the joint.
Presumptive Diagnosis Includes 17-21
- Risk Factors
- Family History
- Erythematous, swollen/tender, painful joints(s)
- Pain assessment using a 5-point Likert scale (0=none, 1=mild, 2=moderate, 3=severe to 4=extreme)
- Evidence of tophi if disease advanced
- sUA measurement-after the flare has passed
- Obesity (high BMI)
- Diet rich in meat and seafood
- High alcohol intake
- Frequent consumption of high fructose corn syrup
- Advanced age
- Postmenopause in women
- Thiazide diuretics
- Low-dose aspirin
- Nicotinic acid
- Cardiovascular disease
- myocardial infarction
- peripheral artery disease
- congestive heart failure
- Chronic kidney disease
- Diabetes or insulin resistance
- Metabolic syndrome