Gout and other Crystal-associated Arthropathies Flashcards
Gout deposits
MSU crystals (needle and rod-shaped, brightly birefringent with negative elongation)
MC early clinical manifestation of gout
Acute arthritis
Most often involved in gout
Metatarsophalangeal joint of the first toe
attacks frequently at night, subside spontaneously within 3-10 days
Confirmatory test of gout
Needle aspiration of involved joints
Characteristics of gouty effusions
cloudy
thick pasty or chalky fluid
Can be useful in assessing the risk of stones
24H urine collection
Overproduction of uric acid
excretion of >800mg of uric acid per 24h on a regular diet
Radiologic findings of gout
cystic changes + well-defined erosions with sclerotic margins + soft tissue masses
on utz: Double contour sign
Given in early gout attack
Colchicine 0.6mg 1 tab q8 and taper or 1.2mg followed by 0.6mg in 1h
Side effect of Colchicine
Diarrhea (d/c immediately)
Effective in polyarticular gout
Glucocorticoids
IL 1B effective in acute gout
Anakinra
Goal of hypouricemic therapy
Normalize uric acid to <300-360 umol/L (5-6 mg/dL)
to prevent recurrence and eliminate tophi
(<6 mg/dL in phil cpg)
Hypouricemic therapy which can be used in patients with good renal function who UNDEREXCRETE uric acid
(<600mg in a 24h urine sample)
Probenacid
not effective for crea >2mg/dL
Best xanthine oxidase inhibitor to lower urate in OVERproducers of urate, urate stone formers and patients with renal disease
Allopurinol
MC age group affected by CPPD
Elderly (30-50% >85 years old)
Pathogenesis of CPPD
Increased production of INorganic pyrophosphate and decreased levels pyrophosphatase in cartilage extracts
Diseases associated with CPPD esp in <50 years old
Hypeparathyroidism Hemochromatosis Hypophosphatemia Hypomagnesemia Gitelman’s
Most frequently affected in CPPD arthropathy
Knee joint
Radiologic finding in CPPD
Chondrocalcinosis or punctate and/or linear radiodense deposits
(may be present in CaOx)
Definitive diagnosis of CPPD
Typical rhomboid or rodlike crystals, weakly positive birefringent in synovial fluid
Gene mutation associated with CPPD
ANKH
Most frequently affected in Calcium Apatite Deposition Disease
Shoulders (Milwaukee shoulders)
Frequently deposit in bursae and tendons
Radiographic findings of calcium apatite
Intra and/or periarticular calcifications with or without erosive, destructive or hypertrophic changes
EM findings of Apatite
clumps of crystals shiny nonbirefringent globules or aggregates
Microscopic findings of CaOx
Bipyramidal or variable, strong birefringence
Treatment in primary oxalosis
Liver Transplantation
Uric Acid Goal
<7 mg/dL males
<6 mg/dL females
( x 60 for umol/L)
Increases risk of gout
Meat + seafood + alcohol
Risk factors for gout
Obesity Hypertension Malignancies Psoriasis CHF
Hypouricemic therapy indications
After 2 attacks
SUA >9mg/dL
Willing ti commit to lifelong therapy
Uric acid stones
With tophi/chronic gout
Most serious side effect of Allopurinol
TEN
Associated risk factors for Apatite
Hyperphosphatemia
CKD
Metastatic Calcification
