11 - Gout and Uric Acid Lithiasis Flashcards
(46 cards)
What is gout?
- An acute arthritic process, which develops from the accumulation of uric acid.
- Intense swelling, pain, redness, heat
How does uric acid accumulate
From an exogenous source, the purine intake contributes
What are the general characteristics of gout?
- Usually affect men older than 25 and women who are post-menopausal
- Initial presentation is usually a painful attack of monoarticular arthritis
- Various precipitating factors (trauma, alcohol, surgery, diet, and drugs)
Most will have gout in the first metatarsal phalangeal joint
What is primary gout?
Primary Gout: may be inherited as idiopathic or secondary to a defect in purine metabolism leading to an overproduction of uric acid.
What is secondary gout?
Secondary Gout: may be the result of an inherited disorder (Lesch-Nyhan or glycogen storage) or the result of over production due to increase of cellular turnover, or in under secretion.
What is on the differential diagnosis for gout?
- Crystal arthropathies
- Infection
- Sarcoidosis
- Trauma
Think about differential as you obtain H&P
What are the symptoms of gout?
- Pain of the involved joint
- Redness
- Swelling
- Mild fever and chills
What are the four phases of gout?
- Asymptomatic Hyperuricemia
- Acute Gouty Arthritis ***
- Intercritical Gout
- Chronic Tophaceous Gout
Describe Asymptomatic Hyperuricemia
High uric acid in system, either high intake or high production, but no symptoms
Describe Acute Gouty Arthritis
Acute Gouty Arthritis ***
- MOST COMMON to diagnose
- Hot, painful, inflamed joint is present
- First attack
- Lasts for 3-7 days
Describe Intercritical Gout
- The period of time after the first gout attack
- You will see sustained high uric acid following attack
- This can last for months to years
- Patient may have another attack, but hard to predict when that may be
Describe Chronic Tophaceous Gout
- High uric acid will remain
- The uric acid starts to collect into “tophi” in soft tissue
- The only way you can evaluate this is with a soft tissue mass, uric acid crystals present
What are the criteria for the diagnosis of acute gout?
A. The presence of characteristic urate crystals in the joint fluid (if a past attack then C1 and C4 also)
B. A tophus proved to contain urate crystals by chemical means or polarized light microscope and C1 and C4
C. Presence of six of the following 12 clinical, laboratory, and radiographic phenomena
What are the 12 clinical, laboratory and radiographic phenomena?
- Maximum inflammation developed within one day
- More than one attack of acute arthritis
- Presents with monoarticular arthritis
- Redness is observed over the affected joint(s)
- First metatarsophalangeal pain or swelling
- Unilateral first metatarsophalangeal joint attack
- Unilateral tarsal joint attack
- Tophus is suspected
- Hyperuricemia
- Asymmetric swelling within a joint
- Subcortical cysts without erosions in radiograph
- Joint fluid culture negative for organisms
What are on the differential for this?
- Fracture
- Osteoarthritis
- Septic joint
- Pseudogout
Describe the gout work-up
- Blood work
- Joint aspiration
Describe the blood work for a gout work-up
Serum uric acid should be between 3-7 mg/dl
Describe the joint aspiration of synovial joint fluid
Synovial fluid analysis
- Fluid will be thick and straw colored during a gout attack
- Glucose will be the same as blood serum during a gout attack
- WBCs or bacteria are NOT present in the joint fluid during a gout attack
Describe the crystals seen in gout
KNOW THIS ***
Negatively birefringent crystals seen under a polarized microscope
More pink with red crystals (slide 13)
Describe the crystals seen in pseudogout
KNOW THIS ***
Weakly positive birefringent rhomboid crystals under polarized scope
More purple with blue crystals (slide 13)
What will you see with tophaceous gout?
- Very red, very inflamed joint superficially
- Large soft tissue mass
- Radiographically, you can see that the first PMTJ is involved too, not just soft tissue
What are the radiographic findings of gout?
- Erosions at the level of the joint
- May need to compare this to other erosive activities
- In gouty arthritis, they will be greater than 5 mm in diameter
- RA will be smaller erosions (less than 5 mm in diameter)
- In RA, you will see cystic changes more proximal to the joint, not right at the joint
- Gout you see all erosion in the joint
So, why the 1st MPJ?
- An increase in uric acid will decrease the solubility resulting in crystal formation
- Trauma of walking initiates a low grade inflammation resulting in a lower pH
- Decrease in temp of toe
- Cooling of the extremities and decrease heart rate while sleep.
How do you treat gout?
Depends on if it is an acute flare up or chronic treatment