Gout and CPPD dx Flashcards
Before starting allopurinol, what do you do?
Order HLA-B 5801 allele
Do this for pts who are high risk for hypersensitivity (DRESS) with allopurinol
Who is at risk for allopurinol hypersensitivity?
CKD, ethnicity (Thai, Han Chinese, Korean)
allopurinol is contraindicated in GFR<30
diuretic use is a risk factor
Allopurinol hypersensitivity
See DRESS (drug reaction, eosinophilia, and systemic symptoms)
Can probenecid be given to patients with CKD and gout
no, needs intact renal function.
Febuxostat
non competitive xanthine oxidase inhibitor ok for mild to moderate CKD and second line after failing allopurinol (with limited approval)
only used for chronic management and NOT for acute gout attack.
Black box warning of febuxostat
increased risk for cardiovascular death and mortality (FDA 2/2019)
Calcium pyrophosphate deposition disease or CPPD is also called
pseudogout and a crystal induced arthropathy.
See rhomboid shaped weakly positively bi refringent crystals on joint fluid analysis
CPPD crystal arthropathy
most commonly affected joint with Calcium pyrophosphate deposition disease
knee
what do you see on XR of knee with Calcium pyrophosphate deposition disease?
chondrocalcinosis - calcium deposition in cartilege
Treatment of Calcium pyrophosphate deposition disease
aspiration of fluid followed by a short course of NSAIDS or intraarticular steroid injection.
if there’s fewer than three joints involved
Before giving a steroid injection to treat someone with CPPD, what should you do first
rule out septic joint based on feer, leukocytosis, examination under Gram stain and culture.
How do you treat pts who have multiple joints involved with CPPD arthropathy?
colchicine (if started within 24 hrs of symptomon onset, NSAIDS and oral steroids).
ineffective to give intraarticular steroid injection with so many joints involved
what medication can you give to prevent future CPPD attacks?
colchicine
refractory cases of CCPD - give immunosuppression with hydroxychloroquine, methotrexate.
can give NSAIDS for pain.
Medications that increase risk for gout
diuretics and low dose aspirin, beta blockers, ACEi and ARBS (except losartan)
risk factors for gout
surgery, trauma, recent hospitalization
volume depletion
diet: high protein foods (meat and seafood), high fat foods, fructose or sweetened beverages
heavy ETOH consumption
underlying medical conditions like HTN obesity CKD and organ transplant
what foods decrease risk for gout:
low fat dairy product
vitamin C>1,500 mg/day
coffee intake >6 cups/day
how do loop diuretics increase risk for gout?
increases serum urate levels through both volume depletion and increased urate reabsorption in proximal tubule.
Thiazide diuretics also raise uric acid levels by acting as a counter-membrane transporter for urate and relatively contraindicated with gout
Gout is associated with
hyperuricemia hypertension obesity alcohol diuretics
Pseudogout is associated with
hypothyroidism hemochromatosis renal osteodystrophy hypomagnesemia hyperparathyroidism, recent parathyroidectomy
Affected joints of gout
1st metatarsal phalangea (50*90%)
ankle
knee
Name the commonly affected joints of pseudogout (CPPD)
knee (most common)
wrist
ankle
Synovial joint analysis of gout
needle shaped negatively birefringent, uric acid crystals
see 2000-100,000 WBC
XR of gout
subcortical bone cysts and possible bony erosions
synovial joint analysis of gout
rhomboidal positively birefringent calcium pyrophosphate crystals with 15-30K WBC