Gout

Gout is a common disorder of uric acid metabolism. It is a medical condition that usually presents with recurrent attacks of acute inflammatory arthritis. Gout is caused by cellular reaction to uric acid and can lead to deposits of monosodium urate crystals in soft tissues and joints.



Types

Primary gout - May occur alone. Accounts for about 90% of cases of the disease.

Secondary gout- May be associated with other medical conditions or medications. Accounts for about 10% of cases of the disease.


Frequency
Approximately 1% of the general population have gout.

Sex
Predominance- 90% male


Symptoms

Gout is associated with considerable pain.

Acute episodes of gout may incapacitate a patient.

Involved joints typically have the following symptoms: swelling, warmth, erythema, and tenderness.

The first metatarsal phalangeal joint is most commonly affected, however other joints can be involved such as the ankle or the knee.


A tophus deposit may develop in the ear.


Causes

Conditions that may cause acute changes in the level of uric acid and may precipitate a gout attack:

• Hyperuricemia
• End-stage renal disease
• Alcohol ingestion
• Disorders that cause high cell turnover with release of purines
• Over consumption of foods high in purines
• Underexcretion of uric acid - renal insufficiency

Long Term Effects

Untreated chronic tophaceous gout can lead to severe joint destruction.

Deposition of uric acid crystal in the kidneys may produce renal failure or obstruction.


Differential Diagnosis

Cellulitis- A severe inflammation of dermal and subcutaneous layers of the skin.

Gonococcal Arthritis- Is caused by infection with Neisseria gonorrhoeae.

Calcium Pyrophosphate Deposition Disease- Is a type of arthritis caused by the deposition of calcium pyrophosphate crystals.

Rheumatoid Arthritis- Is a chronic systemic inflammatory disease that affects the peripheral joints.

Psoriatic Arthritis- Is a chronic inflammatory arthritis that is commonly associated with psoriasis.


Laboratory Studies

Synovial fluid- The physician may aspirate the involved joint to rule out an infectious arthritis and to confirm a diagnosis of gout.

Serum uric acid.

Uric acid in 24-hour urine sample.


Imaging

Routine radiographs reveal punched-out erosions or lytic areas with overhanging edges. These finding are not acute.



Treatment

Acute gout

• Indomethacin- is the traditional Nonsteroidal anti-inflammatory drug (NSAID) of choice for acute gout.
• Colchicine.
• Corticosteroids- May be indicated in those patients who do not tolerate NSAID or Colchicine.

Chronic gout

• Probenecid- For patients who are hypoexcreters of uric acid.
• Allopurinol- For patients who are over producers of uric acid. Allopurinol reduces the generation of uric acid in the body.
• Uloric- Prevents uric acid production and lowers elevated serum uric acid levels.

Diet

Patients with gout should avoid beer and hard liquor. These elevate levels of uric acid and may precipitate attacks of gout.

High purine foods should be consumed in moderation:

• Kidney
• Liver
• Meats
• Shellfish