November 19, 2015 - Hyperuricemia & Gout Flashcards
Levels of Uric Acid (Demographics)
For males, levels of uric acid increases sharply at around 14 years of age and remains high for the rest of their lives.
For females, levels of uric acid remains low until after menopause (around 50 years old) in which it increases sharpy to almost the level of men.
Causes of Hyperuricemia
Primary
Overproduction (10%)
Under-excretion (90%)
Secondary
High cell turnover can cause overproduction (eg. psoriasis)
Diseases Associated with Hyperuricemia
Obesity
Diabetes
Type IV hyperlipidemia
Hypertension
Atherosclerosis
Consequences of Hyperuricemia
Acute gout
Chronic gout
Renal disease
Acute Gout
Peak age of onset is between the 4th and 6th decades of life. It is very uncommon for it to occur in women before menopause.
The big toe is often affected (60%), but the instep, ankles, and knee can also be frequently affected as well.
Often leads to a intercritical period. Always ask if this has happened before when treating a patient.
Intercritical Period
The period of time after the first attack between the second attack.
60% of people have a second attack within the first year, and 90% of people have a second attack within 5 years.
Attacks tend to recur at shorter intervals and eventually enter a phase of chronic polyarticular gout with no pain-free intercritical period.
Diagnosis of Gout
You should suspect on history and physical exam.
The gold standard is synovial fluid analysis demonstrating uric acid crystals within neutrophils.
Polarized Light and Diagnosis
Monosodium urate (gout) crystals will turn yellow if they are parallel to the polarized light and turn blue if they are perpendicular to the polarized light.
Pyrophosphate (pseudo-gout) crystals will turn blue if they are parallel to the polarized light, and yellow if they are perpendicular to the polarized light.
Chronic Tophaceous Gout
A chronic form of gout in which nodular masses of uric acid crystals (called tophi) are precipitate out and are deposited in different soft tissue aras of the body.
Tophi are most commonly formed around the cartilage of the ear, tendons, synovial tissue of bursae, and articular cartilage.
Causes large erosions.
Colchicine
A drug that is administered to lower uric acid levels.
Do not start until at least 2 weeks after an episode of acute gout. It is used to try to reduce the likelihood of another attack during the intercritical period.