Gout and Other Crystal-Associated Arthropathies Flashcards
Most common early clinical manifestation of gout
Acute arthritis
Polarized microscopy alone can identify most typical crystals except this one
Apatite
Most commonly involved joint in gout
1st MTP
Characteristic of monosodium urate crystals on polarized microscopy
Brightly birefringent with negative elongation; needle-shaped
Arthrocentesis of these joints is a useful technique to establish the diagnosis of gout between attacks because MSU crystals can be demonstrated even when they are not acutely involved with gout
1st MTP and knees
Reason why serum uric acid may be normal or low at the time of an acute attack of gout
Inflammatory cytokines can be uricosuric
Excretion of this amount of uric acid per 24 h on a regular diet suggests that causes of overproduction of purine should be considered
> 800 mg in 24 h
Mainstay of treatment during an acute gouty attack
Anti-inflammatory drugs (NSAIDs or glucocorticoids)
Best drug to lower serum urate in overproducers, urate stone formers, and patients with renal disease
Allopurinol
Uricosuric drug that is more effective than probenecid in patients with renal failure
Benzbromarone
Toxicity of allopurinol has been recognized increasingly in patients who use this diuretic
Thiazide
Toxicity of allopurinol has been recognized increasingly in patients who are allergic to these antibiotics
Penicillin and ampicillin
Most serious side effects of allopurinol
TEN, systemic vasculitis, bone marrow suppression, granulomatous hepatitis, renal failure
A specific xanthine oxidase inhibitor that does not require dose adjustment in mild to moderate renal disease
Febuxostat
Duration of colchicine prophylaxis in patients given hypouricemic therapy
Until patient is normouricemic and without gouty attacks for 6 months or as long as tophi are present
A new urate-lowering biologic agent that can be effective in patients allergic to or failing xanthine oxidase inhibitors
Pegloticase
Mutations in this gene can increase elaboration and extracellular transport of pyrophosphate, leading to CPPD arthropathy
ANKH gene
Most frequently affected joint in CPPD arthropathy
Knee
Findings of punctate and/or linear radiodense deposits in fibrocartilaginous joint menisci or articular hyaline cartilage; seen in CPPD arthropathy
Chondrocalcinosis
Polarized light microscopy findings in pseudogout (CPPD arthropathy)
Rhomboid, square, or rodlike crystals with weak positive birefringence
Chondrocalcinosis not due to CPPD deposition in patients with chronic renal failure is due to accumulation of this crystal
Calcium oxalate
Prophylactic treatment for frequent recurrent attacks of pseudogout
Colchicine
Primary mineral of normal bone and teeth
Apatite
Destructive chronic arthropathy of the shoulder in the elderly, associated with apatite deposition disease
Milwaukee shoulder