Gout
Introduction
Gout is a common and painful inflammatory arthritis caused by the deposition of monosodium urate crystals in joints and surrounding tissues usually associated with hyperuricemia, which is an abnormally high level of uric acid in the blood. The prevalence of gout ranges from 1-4% worldwide. Gout is more common in men than women, with a ratio of 3:1 to 10:1. The prevalence of gout increase with age, reaching up to 11-13% prevalence in people older than 80 years. Gout is caused by the deposition of monosodium urate crystals in joints and surrounding tissues due to hyperuricemia. The excreted uric acid form crystals that trigger an inflammatory response.
Clinical Presentation
Gout typically presents as an acute, severely painful, and swollen joint, and overlying skin inflammation. It most commonly affects the first metatarsophalangeal joint (big toe). Other joints, such as the ankles, knees, wrists, and elbows, can also be affected. Acute gout attacks can be triggered by acute changes in uric acid levels, such as the consumption of alcohol or high-purine foods, trauma, dehydration. Gout attacks often occur suddenly and can last for several days to weeks if left untreated. Gouty tophi, which are nodules formed by the deposition of urate crystals in the skin, can also be present in some patient.
Diagnosis
Diagnosis of gout is based on clinical presentation, laboratory tests, and imaging studies. The gold standard for diagnosis is the identification of monosodium urate crystals in synovial fluid or tophi (urate deposits) obtained from the affected joint. Laboratory tests may show elevated serum uric acid levels, but this alone is not diagnostic, as some individuals with hyperuricemia may not develop gout. Imaging studies, such as X-rays, ultrasound can help visualize joint damage and crystal deposits.
Treatment
The treatment of gout involves managing acute attacks and preventing future episodes. Acute attacks are treated with nonsteroidal anti-inflammatory drugs (NSAIDs), colchicine, or corticosteroids to reduce inflammation and pain. Long-term management includes urate-lowering therapy (ULT), such as allopurinol or febuxostat, to reduce serum uric acid levels and prevent crystal formation.
Pseudo Gout
Pseudo gout, also known as calcium pyrophosphate dihydrate (CPPD) crystal deposition disease, is a condition that can mimic gout but is caused by the deposition of calcium pyrophosphate crystals in joints and surrounding tissues. The clinical presentation, diagnosis, and management of pseudo gout are similar to those of gout, but the underlying pathophysiology and crystal composition are different.
Complications
Complications of gout can include joint damage, kidney stones. Gout has also been associated with ocular abnormalities, including retinal complications and an increased risk of macular degeneration. In rare cases, gouty tophi can form in unusual locations, such as the sinus tarsi, subtalar joint, or even the retina, mimicking other pathologic conditions.
Lifestyle Modification
Lifestyle modifications can help reduce the risk of gout attacks and improve overall health. These include limiting alcohol consumption, staying well-hydrated, and consuming a balanced diet low in purine-rich foods (e.g., red meat, seafood, and organ meats).
Here are some key points to consider when educating patients about dietary modifications for gout:
1. Limit purine-rich foods: High-purine foods can increase uric acid levels, leading to gout attacks. Patients should avoid or limit their intake of organ meats (e.g., liver, kidney, sweetbreads), certain seafood (e.g., anchovies, shellfish, sardines, tuna), and high-purine vegetables (e.g., asparagus, spinach).
2. Alcohol consumption: Alcohol, particularly beer and grain liquors, can increase the risk of gout attacks.
3. Hydration: Staying well-hydrated can help flush out uric acid and prevent kidney stones, which are potential complications of gout
By following these dietary modifications, patients can better manage their gout and reduce the risk of gout attacks.
Common Misunderstandings
Some common misunderstandings about gout include the belief that it only affects the big toe. In reality, gout can affect various joints. Another common misunderstanding is that high uric acid levels in the blood always indicate gout, but not all individuals with hyperuricemia develop gout. Additionally, blood tests for uric acid levels are not diagnostic tests for gout, as the gold standard for diagnosis is the identification of monosodium urate crystals in synovial fluid or tophi.