Gouty Arthritis Flashcards
What is gout?
a metabolic disease of a heterogeneous nature, often familial, associated with abnormal amounts of urates in the body and characterized early by a recurring acute arthritis, usually monoarticular, and later by chronic deforming arthritis.
Associated hyperuricemia (serum uric acid > 6.8) is due to what?
An overproduction or underexcretion of uric acid
Gout is most common in what type of population?
Pacific Islanders (Filipinos and Samoans)
What are the 2 types of gout?
- primary
- secondary
What is primary gout linked to?
Several genes, making it hereditary
What is secondary gout linked to?
Acquired causes of hyperuricemia, such as medications, myeloproliferative disorders, multiple myeloma, hypothyroidism, etc.
Ingestion of what promotes hyperuricemia?
alcohol
What type of patients often suffer attacks of gout? Why?
Hospitalized patients, because of changes in diet, fluid intake, or medications
About __% of patients with primary gout are men
90
When does gout onset typically occur in women?
postmenopausal
What is the characteristic nodular deposition of monosodium urate monohydrate crystals with an associated foreign body reaction called?
the tophus
What is acute inflammation of gout believed to be initiated by?
the ingestion of uncoated urate crystals by monocytes and synoviocytes
What are important factors in precipitating acute gout?
Rapid fluctuations in serum urate levels, either increasing or decreasing
What is characteristic of chronic stage gout?
Tophaceous invasion of the surrounding tissue, with structural derangement and secondary degeneration (OA)
Uric acid kidney stones are present in -% of patients with gouty arthritis
5-10
What causes chronic urate nephropathy?
the deposition of monosodium urate crystals in the renal medulla and pyramids
What are the signs and symptoms of acute gouty arthritis?
- Sudden in onset
- Nocturnal
- More than one joint may be involved
- Involved joints are swollen and exquisitely tender
- Fever
Which joint is the most susceptible to gouty arthritis?
MTP joint of the great toe (“podagra”)
Where can tophi be found?
- external ears
- feet
- olecranon
- prepatellar bursa
- hands
Gout can evolve into chronic polyarthritis of upper and lower extremities that mimics what disease?
rheumatoid arthritis
A single uric acid determination during an acute flare of gout is normal in up to __% of patients. Therefore a normal serum uric acid level does not exclude gout.
25
Sodium urate crystals in joint fluid or material aspirated from a tophus are ____ shaped and _____ bifringent.
needle
negative
What are the differential diagnoses associated with acute gout?
- Cellulitis
- Pyogenic arthritis
- Pseudogout
What is the differential diagnosis associated with chronic gout?
Chronic rheumatoid arthritis
How should asymptomatic hyperuricemia be treated?
it should not be treated
How should an acute attack of gouty arthritis be treated?
- NSAIDS (Indomethacin and Naproxen)
- Colchicine
- Corticosteroids
- Interleukin-1 inhibitors
What is the goal of treatment between gouty arthritis attacks?
Minimize urate deposition in tissues, which causes chronic tophaceous arthritis, and to reduce the frequency and severity of recurrences
What individuals are more likely to benefit from pharmacological treatment?
- Mild chronic kidney disease
- Multiple and frequent attacks of gout
- Higher uric acid level
- Tophaceous gout
Patients should avoid ___-purine diets
high
True or False
Thiazide and loop diuretics, niacin, and aspirin should be avoided in patients with gout
True
What are the 2 indications for daily administration of colchicine?
- For individuals with mild hyperuricemia and only occasional attacks of gout
- When urate-lowering therapy is started
What are the 3 indications for urate-lowering therapy?
- frequent acute arthritis (two or more episodes per year)
- tophaceous deposits
- chronic kidney disease (stage 2 or worse)
The goal of urate-lowering therapy is to maintain the serum uric acid at or below _ mg/dL
6
What are the 3 classes of agents that can be used to lower the serum uric acid?
- Xanthine oxidase inhibitors
- Uricosuric agents
- Uricase
What are the 2 xanthine oxidase inhibitors?
Allopurinol and febuxostat
How do allopurinol and febuxostat lower plasma uric acid levels?
By blocking the final enzymatic steps in the production of uric acid
What is the most frequent adverse effect of allopurinol?
precipitation of an acute gouty attack
What is the most frequent adverse effect of febuxostat?
abnormal liver tests
How do uricosuric agents
lower plasma uric acid levels?
by blocking the tubular reabsorption of filtered urate, thereby increasing uric acid excretion by the kidney
What is the uricosuric agent of choice in the US?
Probenecid
What are the contraindications of Probenecid?
- patients with a creatinine clearance < 50 mL/min
- history of nephrolithiasis (uric acid or calcium stones)
- overproduction of uric acid (>800 mg in 24 hours)
What is the uricase enzyme that must be administered IV?
Pegloticase
Why do hyperuricemia and gout tend to develop in transplant patients?
because they have decreased kidney function and require drugs that inhibit uric acid excretion
