Gout is a metabolic disorder characterized by elevated serum uric acid levels and deposits of urate crystals in synovial fluids and surrounding tissues in joints. It is a type of arthritis that is characterized by sudden, severe attacks of joint pain with redness, warmth, and swelling in the affected area. It usually attacks only one joint at a time. It most often strikes the joint of the big toe, where it is also known as podagra, but other toes can also be involved.
Gout is caused initially by an excess of uric acid in the blood (hyperuricemia). Uric acid is produced in the body through the breakdown of purines specific chemical compounds that are found in certain foods such as meat, poultry and seafood.
Normally, uric acid dissolves in the blood and is excreted from the body in urine via the kidneys. If too much uric acid is produced or not enough is excreted then it can build up and form the needle-like crystals that cause inflammation and pain in the joints and surrounding tissue.
There are a number of factors that can increase the likelihood of hyperuricemia, and therefore gout:
Age and gender: Men produce more uric acid than women. But after menopause, the uric acid level in women is equal to men.
Genetics: A family history of gout increases the likelihood of the condition developing.
Lead exposure: Chronic lead exposure has been linked in some cases to gout.
Medications: Certain medications can increase the levels of uric acid in the body, such as diuretics and drugs containing salicylate, Niacin etc.
Weight: Being overweight increases the risk as there is more tissue in the body for turnover or breakdown, leading to the production of excess uric acid.
Other health problems: If the kidneys are unable to eliminate waste products adequately (renal insufficiency) then uric acid levels can remain high. Other conditions that can contribute are high blood pressure (hypertension), diabetes and hypothyroidism.
Gout is a disorder of purine metabolism, and occurs when its final metabolite,uric acid, crystallizes in the form of monosodium urate, precipitating in joints, on tendons, and in the surrounding tissues. These crystals then trigger a local immune- mediated inflammatory reaction, with one of the key proteins in the inflammatory cascade being interleukin. An evolutionary loss of uricase, which breaks down uric acid, in humans and higher primates has made this condition common.
The triggers for precipitation of uric acid are not well understood. While it may crystallize at normal levels, it is more likely to do so as levels increase. Other factors believed important in triggering an acute episode of arthritis include cool temperature, rapid changes in uric acid levels, acidosis, articular hydration and extracellular matrix proteins such as proteoglycans, collagens and chondroitin sulfate. Rapid changes in uric acid may occur due to a number of factors, including trauma, surgery, chemotherapy, diuretics, and stopping or starting allopurinol. Calcium channel blockers are associated with a lower risk of gout as compared to other medications for hypertension.
The goals of treatment for gout are fast pain relief and prevention of future gout attacks and long-term complications, such as joint destruction and kidney damage.
NSAIDs: NSAIDs may control inflammation and pain in people with gout. NSAIDs include indomethacin, ibuprofen, naproxen, and etoricoxib.
Colchicine: A type of pain reliever that effectively reduces gout pain, especially when started soon after symptoms appears.
Corticosteroids: Corticosteroid medications, such as the drug prednisone, may control gout inflammation and pain. Corticosteroids may be administered in pill form, or they can be injected into joint. Corticosteroids are generally reserved for people who cannot take either NSAIDs or colchicine.
Medication that improves uric acid removal: Probenecid improves kidney’s ability to remove uric acid from body. This may lower uric acid levels and reduce risk of gout, but the level of uric acid in urine is increased.
Pegloticase: This medicine is for gout that has lasted a long time and has not responded to other treatment.
Symptoms of gout include sever pain, bone erosion, redness and swelling in joints, often the big toe.