Ch 3 - Rheumatology: Infectious Arthritides Flashcards
What is the clinical presentation of septic arthritis?
– Rapid onset of moderate to severe Monoarticular, joint pain, erythema, and decreased ROM
– Leukocytosis
– Fevers/chills, sepsis
What is the most common joint involved in septic arthritis?
Knee
What are risk factors for septic arthritis?
– Age
– Prosthetic joints/foreign body
– Comorbidities such as anemia, chronic diseases, hemophilia
What is the most common organism causing septic arthritis in adults?
Neisseria gonorrhea
What is the most common organism causing septic arthritis in children?
Staphylococcus aureus
What are causes of septic arthritis in children?
Otitis
Infected IV lines
What are causes of septic arthritis in Neonates and > 2 years old?
S. aureus
Group B strep
What are causes of septic arthritis in 6 months to 2 years old?
Haemophilus influenza
What is the most common organism causing septic arthritis in RA?
S. aureus
What are lab findings of septic arthritis?
Elevated WBC, ESR, CRP
What are early radiographic findings of septic arthritis?
Soft-tissue swelling
What are late radiographic findings of septic arthritis?
Joint space narrowing Erosions Gas formation (Escherichia coli, Clostridium perfringens)
Describe normal joint fluid analysis.
Viscosity: high Color: colorless Clarity: translucent WBC: <200 PMN%: <25 Culture: negative Mucin clot: good Glucose: = to blood
Describe non-inflammatory joint fluid analysis.
Viscosity: high Color: straw Clarity: translucent WBC: <5,000 PMN%: <25 Culture: negative Mucin clot: good Glucose: = to blood
Describe inflammatory joint fluid analysis.
Viscosity: low Color: yellow Clarity: translucent/ opaque WBC: 1,000-75,000 PMN%: >50 Culture: negative Mucin clot: fair Glucose: <50mg/dL lower than blood glucose
Describe septic joint fluid analysis.
Viscosity: variable Color: turbid-yellow Clarity: opaque WBC: >100,000 PMN%: >85 Culture: positive Mucin clot: poor Glucose: >50mg/dL lower than blood glucose
What are viral causes of septic arthritis?
Rubella
Infectious hepatitis
When are fungus causes of septic arthritis seen?
Seen in immunocompromised adults
What is Pott’s disease?
TB spondylitis
What is affected in Pott’s disease?
Lower thoracic/upper lumbar region
What causes kyphotic deformities in Pott’s disease?
Anterior vertebral body preferentially affected
What is affected in TB arthritis?
Hips and knees
What is Phemister’s triad?
Radiographic findings of TB arthritis
– Juxta-articular osteoporosis
– Marginal erosions
– Joint space narrowing
What causes Lyme disease?
Tick-borne infection from Borrelia burgdorferi
What is the clinical presentation of Lyme disease?
– Erythema migrans (“bull’s eye” rash)
– Cardiac, neurologic, articular manifestations
– Bite>rash> systemic disease> neurologic involvement
– Intermittent migratory episodes of polyarthritis
What joint does Lyme disease commonly affect?
Knee
How is Lyme disease diagnosed?
– Synovial fluid—inflammatory
– ELISA, Western blot analysis
What is the treatment of Lyme disease?
Adults: doxycycline
Children: amoxicillin
