Gout (microcrystalline arthritis due to uric acid crystals)

Gout is a common form of inflammatory arthritis characterized by excess uric acid in the blood that causes crystals to form in the joints. These crystals can cause inflammation and pain in the joints, especially at the base of the big toe, although they can affect other joints as well. In this answer, we will discuss the diagnosis, phenotypes, and treatment of gout in 2000 words.


Diagnosis:

The diagnosis of gout is based on a combination of the patient's history, physical examination, and laboratory test results. Patients with gout may have recurrent episodes of acute inflammation in one or more joints, which can last for days or weeks. The pain is usually severe and may be associated with redness, warmth, and tenderness in the affected joint. Often, patients can identify a trigger that precedes gout episodes, such as excessive intake of alcohol or purine-rich foods.

On physical examination, the doctor will look for signs of inflammation in the affected joints. They may also look for tophi, which are deposits of uric acid crystals under the skin, in places like the ear or elbow. In addition, the doctor may order laboratory tests to confirm the diagnosis, including elevated levels of uric acid in the blood, the presence of uric acid crystals in the synovial fluid of the affected joint, and elevation of C-reactive protein and the rate of erythrocyte sedimentation rate (ESR), which are indicators of inflammation.


Phenotypes:

There are two main phenotypes of gout: acute gout and chronic gout. Acute gout is characterized by recurrent episodes of acute inflammation in one or more joints, which can last for days or weeks. Chronic gout, on the other hand, occurs when uric acid crystals build up in the joints over a long period of time, which can lead to joint damage and deformity.


Treatment:

Gout treatment aims to reduce pain, inflammation and prevent future attacks. Treatment is divided into two phases: the acute phase, to treat an acute attack of gout, and the maintenance phase, to prevent future attacks and reduce the buildup of uric acid in the body.

In the acute phase, medications such as colchicine or non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen or naproxen are used to relieve pain and inflammation. If pain and inflammation are severe, oral corticosteroids or corticosteroid injections may be given.

In the maintenance phase, the goal is to reduce the amount of uric acid in the body to prevent future attacks. This can be accomplished through diet and lifestyle changes, as well as medication.

Diet changes may include limiting your intake of foods high in purines, such as red meat, shellfish, and alcoholic beverages. It is also recommended to increase fluid intake to help remove excess uric acid from the body.

Medications used in the maintenance phase include xanthine oxidase inhibitors, such as allopurinol and febuxostat, which reduce the amount of uric acid in the body and are often the cornerstone of treatment. Uricosurics, such as probenecid, may also be helpful as they help the body eliminate uric acid through the urine.