GOUT

General:  Gout is the most common type of inflammatory arthritis, affecting 8 million people in the USA every year.  Gout occurs when the body has difficulties getting rid of a substance called uric acid.  When uric acid builds up in the bloodstream, it can turn into crystals that deposit in a joint.  This causes sudden episodes of severe joint pain.  Gout is most frequently found in the foot, at the joint that forms the base of the great toe.  Gout also can affect other joints, such as the knee, and can form in fluid pockets called bursae outside the joints.  Gout attacks usually affect one joint, but it doesn’t have to be the same joint every time.

Causes:  Uric acid is a waste product from the digestion of foods high in purine content.   Uric acid leaves the digestive tract, travels through the bloodstream, and gets deposited into urine by the kidneys.   Gout occurs when the kidneys are unable to properly get rid of uric acid.  Genetics may cause this kidney malfunction.  Eating purine-rich foods like shellfish and organ meats, as well as alcohol and sugary foods, can increase risks of a gout attack.

When uric acid crystallizes in a joint, the immune system responds with an intense inflammatory reaction that causes pain and swelling.  With repeated attacks, permanent joint destruction and deformity can occur.  Tophi, uric acid nodules, may also form at the joint, which can be painful and can affect joint function. 

Men and postmenopausal women are at increased risk to have a gout episode.  Female sex hormones increase the kidneys’ ability to remove uric acid, so premenopausal women are less likely to have gout.   

Certain health conditions increase the risk of gout, such as some chronic health conditions like diabetes and kidney disease, obesity, and medication use.  

Symptoms:  Gout is characterized by sudden, severe, intense pain, swelling, and redness in one joint.  Movement and weight bearing will typically be painful and limited.  Although the big toes is usually the target, other joints can have gout attacks, including the knees, ankles, wrists, and fingers.  The pain is usually worst in the first 24 hours.  Symptoms can last days or weeks and then gradually resolve. 

Dx:  The most reliable diagnosis of gout is the detection of uric acid crystals in the joint.  This is done via arthrocentesis, a procedure where a needle is in into the joint and extracting fluid that is then examined under a microscope.  

Blood tests can detect high uric acid levels that predict risk of acquiring gout.  However, uric acid levels are not always elevated during an acute gout attack.   Urine testing for uric acid content over 24 hours can be done as well.   

X-rays may be helpful to rule out other medical conditions.  Tophi are visible on x-rays.

Treatment:  First-time gout attacks are geared towards decreasing inflammation.  Antiinflammatory medications are considered first-line treatments.  Corticosteroids also decrease inflammation and can be prescribed in the form of oral tablets or a single joint injection.   Colchicine can quickly decrease inflammation in gout when given soon after symptoms develop, but can cause nausea, vomiting, and diarrhea even with a single medication dose. 

When gout attacks are recurrent and frequent, permanent damage can occur because of persistent high levels of uric acid.  Therefore, a long-term plan to decrease uric acid is needed.  The goal is to decrease blood uric acid to less than 6 mg/dL.  The best initial strategy is to change the diet to include more fluids, fruitsm and vegetables, and less purine-rich food (including fish, shellfish, organ meats).   Medications can be effective, and can be continued even during gout flare-ups.  Xanthine Oxidase Inhibitors (XOI) like allopurinol decrease uric acid production.  They must be used with caution in lower amounts if there is kidney disease.  Certain ethnic groups (Han Chinese, Thai) cannot take allopurinol.   Other medications like Probenecid increases the removal of uric acid through urine, but side effects are frequent.  Colchicine can be used long-term as a maintenance medication if tolerated.  In difficult cases of gout where standard medications are ineffective, rheumatologists may recommend an IV treatment (pegloticase) that changes uric acid to a different substance.  

Self-management: There are many options for people to try at home to help prevent and treat gout.