Infectious arthritis Flashcards
(40 cards)
What are the types of infectious arthritis
Bacterial, viral, fungal, parasitic, mycobacterial, Lyme Disease, Rheumatic fever, HIV associated
Acute bacterial arthritis usually affects what parts of the body?
Usually a=only affects one joint, the knee
How does bacterial arthritis most commonly get in the joints?
hematogenous seeding of the synovial membrane. Remember that the joint space is rich in vasculature and lacks a basement membrane, both of which allow organisms easy access to joints
BEsides hematogenous seeding, what is another route of spread for bacterial arthritis?
Contiguous spread from a bursitis, cellulitis, or osteomyelitis
Note: Bacterial arthritis is a medical emergency.
YES IT IS
What is the least common, and third type, or spread for bacterial arthritis
From penetrating trauma (cat bite, nail, plant, thorn, etc..) something that is penetrating into the joint.
Two categories of bacterial arthritis?
Gonococcal and Non-gonococcal
What is the major virulence factor for N. Gonorrhaea
Protein 1A. I
What does protein 1A do?
It inactivates the hosts complement system
It also prevents phagosome lysosome fusion in neutrophils which means that gonorrheae can stay alive inside the phagosome.
Clinica presentation of disseminated gonococcal arthritis?
Migrating arthritis. These patients get tenosynovitis of wrists, ankles, fingers, toes. They also have dermatitis and a fever in most cases.
What type of patient presents with disseminated gonococcal arthritis?
Usually the pt is young and healthy. Usually sexually active.
Are blood cultures a good way to test for disseminated gonococcal arthritis?
NO! Bllod cultures are rarely positive.
Be sure to recognize the skin lesion from disseminated gonococcal arthritis
ok
What are teh major risk factors for non gonococcal arthritis?
Since this is not related to gonorrhaea, it is not sexually transmitted.
- Non-gonococcal arthritis is most common in people who have predisposing co-morbidity, such as diabetes, renal failure, HIV,hemophilia, etc…
- Another predisposing factor would be recent joint surgery, a skin infection, an immunosuppresed state. etc…
- IV DRUG USE
What is the most common cause of non-gonococcal arthritis infection?
Staph aureus, followed by streptococcus, after this is gram neg bacteria
Most common cause of prosthetic joint infection is
coagulase negative staph aureus
Most common cause of non-gonococcal arthritis in IV drug abusers is?
Pseudomonas and candida
In sickle cell anemia, what is the most common cause of non-gonococcal arthritis?
Salmonella
Virulence factors of Staph aureus
Collagen binding protein Clumping factor A and B protein A Toxic shock syndrome toxin-1 Enterotoxins
Clinical presentation of non-gonococcal arthritis
Monoarticular, Usually affects large joints like knees and hips.
Patients will generally appear sick,,,they have a fever
What MUST you do with bacterial arthritis?
ASPIRATE because bacterial arthritis will generally have purulent synovial fluid.
What other lab signs will bacterial arthritis include?
Very low glucose, gram positive in 60-80% of cases
What is the most common cause of viral arthritis in the US
Parvo B19
Common presentation of Parvo B19
- Slapped cheek
- PIP swelling, MCP swelling, knee, ankle
