Gout is characterized by acute and recurrent arthritis mediated by the formation of monosodium uric acid (MSU) crystals within the joints and surrounding tissues. This results in pain, erythema, and inflammation. Elevated serum uric acid (SUA) concentrations are a result of a defect in purine metabolism, a decrease in uric acid excretion, increased nucleic acid turnover, or increased purine production. Uric acid is a metabolic by-product of purine compounds derived from dietary sources or the breakdown of DNA within the body’s cells. Uric acid is excreted by the kidneys and can accumulate if production exceeds excretion. A majority of patients with gout accumulate excessive uric acid due to underexcretion of the compound. Regardless of the cause, excessive intake of high purine foods contributes to hyperuricemia and gout exacerbations (Table 48-1).
TABLE 48-1Dietary Components Which May Affect Serum Uric Acid (SUA) Levels |Favorite Table|Download (.pdf) TABLE 48-1Dietary Components Which May Affect Serum Uric Acid (SUA) Levels
|Increased SUA |
|• Red and organ meat (liver, kidney), seafood (shellfish, anchovies), beer, and spirits |
|• Sugar-sweetened soft drinks and fructose |
|Decreased SUA |
|• Vitamin C |
|• Coffee |
SUA monitoring is an important assessment for gout. SUA concentrations are higher with increasing age, blood pressure, body weight, and alcohol intake. Gout flares can occur in individuals with normal SUA levels and elevated SUA concentrations do not always lead to the development of gout.
Gout is a self-limiting monoarthritis disease involving a lower extremity joint (Table 48-2). Additionally, 90% of patients experience podagra (acute attacks in the great toe). Symptoms develop rapidly and include excruciating pain, erythema, warmth, and swelling near the affected joint. Although acute attacks often occur spontaneously, they can be precipitated by stress, infection, surgery, or ingestion of alcohol or medications. Exacerbations initially occur infrequently; however, gout is a chronic disease with recurrent flare-ups which increase in frequency over time. If untreated, an acute gouty attack may last 1 to 2 weeks, followed by an asymptomatic period.
TABLE 48-2Clinical Signs and Symptoms of Gout |Favorite Table|Download (.pdf) TABLE 48-2Clinical Signs and Symptoms of Gout
|• Affected joint(s) are swollen, erythematous, and warm |
|• Mild fever |
|• Tophi may be present in chronic, severe disease (usually on ears, hands, wrists, elbows, or knees) |
|• Severe pain, swelling, and warmth in the affected joint(s) |
|• Attack is usually monoarticular; most common sites are metatarsophalangeal and knee joints |
|• Elderly patients may exhibit atypical presentation, such as insidious onset of symptoms and polyarticular joint involvement, often involving the hand or wrist joints |
In addition to traditional gout symptoms, patients may experience other complications including: