Rheum - Monoarticular Arthritis Flashcards
Why is acute monoarthritis a medical emergency?
Could be infectious arthritis, which could lead to joint destruction and severe morbidity
Patient with suspected gout. Next step? Best initial treatment?
Aspirations of joints to send food for cell count, culture, Crystal analysis.
If infection needs drainage. If crystal induced arthritis treat with colchicine, NSAIDs, or corticosteroids
Differential for monoarthritis?
- Infection (bacterial, fungal, lime disease, TB)
- Crystal induced arthritis (gout and pseudogout)
- Systemic disease (rheumatoid arthritis or lupus)
- Noninflammatory (trauma, osteoarthritis)
Gout most commonly involves? Pseudogout?
First MTP joint, ankle, midfoot, or knee
Knee, wrist, first MTP joint
Findings in gonococcal arthritis?
- Migratory arthralgias and tenosynovitis on wrist and hands
- Pustular skin lesions
- Purulence
Location of gonococcal versus nongonococcal septic arthritis?
Wrists and hands versus large weight-bearing joints (knee and hip)
True arthritis versus bursitis?
Swelling, redness, painful limitations during active and passive motion
Versus
Full range of passive motion
Noninflammatory joint effusions: WBC count? Percentage of PMNs?
1000 to 2000. Less than 50% PMNs
Description of Gout versus pseudogout crystals?
Intracellular (within PMN), yellow, needle shaped, negatively birefringent crystals
Vs
Blue, Short & rhomboid, weakly positive birefringent crystals
Typical culture findings in gonococcal arthritis?
Negative joint fluid cultures but positive blood/skin lesion cultures
Normal joint aspirate volume? Viscosity? Color? Clarity? Leukocytes? PMNs? Culture? Glucose?
<25, Negative, equal to blood
Changes to joint aspirate findings in noninflammatory causes?
aspirate volume? Viscosity? Color? Clarity? Leukocytes? PMNs? Culture? Glucose?
Volume >1 mL
Straw to yellow color
50-10,000 leukocytes
Changes to joint aspirate findings in inflammatory causes?
aspirate volume? Viscosity? Color? Clarity? Leukocytes? PMNs? Culture? Glucose?
Volume >1 mL Low viscosity Yellow color Translucent clarity 2000 – 75,000 leukocytes Greater than 50 PMNs About 50 mg/dL less glucose
Changes to joint aspirate findings in septic causes?
aspirate volume? Viscosity? Color? Clarity? Leukocytes? PMNs? Culture? Glucose?
>1 mL Variable viscosity Variable color Opaque clarity >100,000 leukocytes Greater than 85% PMNs Positive cultures 50 mg/dL lower glucose
X-ray finding that suggests monoarthritis etiology?
Chondrocalcinosis (linear calcium deposition in joint cartilage) suggests pseudogout
Treatment for gonococcal arthritis?
Ceftriaxone
Typical cause of nongonococcal septic arthritis? Treatment?
Staph aureus. Nafcillin or vancomycin
Stages of gout?
- Asymptomatic hyperuricemia
- Acute gouty arthritis (severe monoarticular pain, often at night in typical joints)
- Intercritical gout (Period between attacks that last 1 to 2 years?
- Chronic tophaceous gout (after 10+ years of acute intermittent gout, critical periods no longer asymptomatic and joints have chronic swelling)
Treatment for each stage of gout?
- No specific treatment
- Indomethacin or oral colchicine every hour (steroid injection if patient has renal insufficiency)
- Prevention – avoid meat and alcohol, switch off thiazides, probenecid, allopurinol
Stage four. Same treatment as acute attack with the addition of allopurinol to resolve tophi
The most common cause of monoarthritis in patient younger than 40? Most useful diagnostic test?
Gonococcal. Urethral, cervical or pharyngeal culture.
Patient with joint aspirate that reveals numerous leukocytes and PMNs but no organisms on gram stain. Few negatively birefringent crystals. Treatment?
Not enough information to rule out infection. Treat with IV antibiotics
Causes for gouty attacks?
##Overproduction #Increased cell turnover (cancer, chemo, hemolysis, psoriasis) # enzyme deficiency (Lesch-Nyhan, glycogen storage disease)
##underexcretion #renal insufficiency #Acidosis #thiazides #ASA
Uric acid levels in gout pts?
#elevated at some point in 95% of patients #a single level during an attack is elected in 75% of patients
Which is better - NSAIDs vs steroids vs colchicine in acute attack?
When steroids?
NSAIDs better then steroids then colchicine
#No response to NSAIDs #renal insufficiency
