Description/Etiology
Gout is an inflammatory arthritic condition caused by excessive production and/or decreased
excretion of uric acid (i.e., a by-product of purine metabolism); both of which result in
hyperuricemia. In gout, crystals of monosodium urate (MSU) are deposited in joints and
other tissues, resulting in chronic arthritis, soft tissue masses called tophi, and renal damage.
Gout attacks are extremely painful and associated with decreased quality of life (QOL).
Gout caused by uric acid overproduction may result from disorders that cause high
cell turnover with release of purines (e.g., myeloproliferative and lymphoproliferative
disorders, psoriasis, tissue lysis in chemotherapy, hemolytic and pernicious anemia, obesity),
overconsumption of high-purine foods (for details, see Risk Factors, below), and rarely,
a genetic disorder (e.g., Lesch-Nyhan syndrome, glucose-6-phosphatase deficiency [also
called von Gierke disease]). Gout caused by underexcretion of uric acid may result from
renal insufficiency, hypothyroidism, hyperparathyroidism, certain drugs (for details, see Risk
Factors, below), chronic ethanol abuse, and starvation.
The three stages of gout are as follows:
› Acute gouty arthritis (commonly called a gout attack), characterized by hyperuricemia,
intense pain, and swelling in the joints. Any joint can be affected, but the big toe is the
joint most commonly affected at presentation. Attacks often begin at night and usually
subside within 10 days. Duration and frequency of attacks may increase over time
› Intercritical gout, in which patients are asymptomatic. Several years may elapse between
attack