Rheumatology: Crystal Arthroplasties Flashcards
Give a general definition of gout
Gout is a group of diseases where there is a tissue deposition of monosodium urate crystals due to hyperuricemia.
What’s the difference between gout and asymptomatic hyperuricemia?
Gout is an acute or chronic arthritis that arises as a result of MSU crystals whereas asymptomatic is exactly what it sounds like, you have elevated uric acid without any resulting symptoms.
What are the 4 stages of gouty arthritis?
1) Asymptomatic hyperuricemia
2) Acute gouty arthritis
3) Intercritical gout
4) Chronic tophaceous gout
What are the classic symptoms of acute gouty arthritis?
Usually it’s an abrupt onset of a red swollen joint, commonly the first MTP joint (termed podagra, like viagra but for a joint). They tend to resolve within 3-10 days. The common joints where this occurs are “cold” joints (more peripheral joints) because the crystals are less soluble there.
What’s intercritical gout?
This it the time inbetween acute attacks of gout
What are the clinical symptoms of chronic tophaceous gout?
You get subcutaneous, synovial, or subchondral deposits of MSU crystals on bone that form tophi, or bump like structures. Tophi are common on fingers/toes, the olecranon process, and the extensor surface of the forearm.
Is gout more common in males or females? When does it commonly occur in males? Females?
More common in males. In males, most commonly after the 3rd decade, most common in 5th decade. In females, more common after menopause. It occurs in about 2% of males and females in those age brackets.
Describe the typical synovial fluid findings in gout
The synovial fluid will have MSU crystals that are needle shaped and yellow. It will also show signs of inflammation, with 20,000-100,000 WBC/mm.
What is the major issue in terms of uric acid management in gout?
In 90% of cases, patients are UNDEREXCRETERS of uric acid (as opposed to over producers)
What percentage of filtered uric acid is normally excreted?
10%
What 2 mutations can lead to overproduction of uric acid?
1) Superactive PRPP synthetase
2) Deficiencies of HGPRT (complete HGPRT deficiency leads to Lesch-Nyhan syndrome)
Where are MSU crystals typically more soluble?
In warmer joints, just compare it to solubility in general. Things typically dissolve better in warmer solutions.
Why do the MSU crystals lead to inflammation?
They interact with the synovial lining tissues, such as mast cells and monocytes which promote inflammation. This process is dependent on PMNs. The crystals may also activate complement.
What kind of bases are associated with gout? How can the intake of these bases be modified to treat gout?
Purines. Foods such as shellfish and meats as well as alcohol can be decreased to try to decrease the chance of a gout flare up. However, diet isn’t too significant of a factor.
What is the best way to treat acute gouty arthritis?
NSAIDS
