Infectious arthritis

Question 1

What are the types of infectious arthritis

Answer 1

Bacterial, viral, fungal, parasitic, mycobacterial, Lyme Disease, Rheumatic fever, HIV associated

Question 2

Acute bacterial arthritis usually affects what parts of the body?

Answer 2

Usually a=only affects one joint, the knee

Question 3

How does bacterial arthritis most commonly get in the joints?

Answer 3

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

Question 4

BEsides hematogenous seeding, what is another route of spread for bacterial arthritis?

Answer 4

Contiguous spread from a bursitis, cellulitis, or osteomyelitis

Question 5

Note: Bacterial arthritis is a medical emergency.

Answer 5

YES IT IS

Question 6

What is the least common, and third type, or spread for bacterial arthritis

Answer 6

From penetrating trauma (cat bite, nail, plant, thorn, etc..) something that is penetrating into the joint.

Question 7

Two categories of bacterial arthritis?

Answer 7

Gonococcal and Non-gonococcal

Question 8

What is the major virulence factor for N. Gonorrhaea

Answer 8

Protein 1A. I

Question 9

What does protein 1A do?

Answer 9

It inactivates the hosts complement system
It also prevents phagosome lysosome fusion in neutrophils which means that gonorrheae can stay alive inside the phagosome.

Question 10

Clinica presentation of disseminated gonococcal arthritis?

Answer 10

Migrating arthritis. These patients get tenosynovitis of wrists, ankles, fingers, toes. They also have dermatitis and a fever in most cases.

Question 11

What type of patient presents with disseminated gonococcal arthritis?

Answer 11

Usually the pt is young and healthy. Usually sexually active.

Question 12

Are blood cultures a good way to test for disseminated gonococcal arthritis?

Answer 12

NO! Bllod cultures are rarely positive.

Question 13

Be sure to recognize the skin lesion from disseminated gonococcal arthritis

Answer 13

ok

Question 14

What are teh major risk factors for non gonococcal arthritis?

Answer 14

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

Question 15

What is the most common cause of non-gonococcal arthritis infection?

Answer 15

Staph aureus, followed by streptococcus, after this is gram neg bacteria

Question 16

Most common cause of prosthetic joint infection is

Answer 16

coagulase negative staph aureus

Question 17

Most common cause of non-gonococcal arthritis in IV drug abusers is?

Answer 17

Pseudomonas and candida

Question 18

In sickle cell anemia, what is the most common cause of non-gonococcal arthritis?

Answer 18

Salmonella

Question 19

Virulence factors of Staph aureus

Answer 19

Collagen binding protein
Clumping factor A and B
protein A
Toxic shock syndrome toxin-1
Enterotoxins

Question 20

Clinical presentation of non-gonococcal arthritis

Answer 20

Monoarticular, Usually affects large joints like knees and hips.
Patients will generally appear sick,,,they have a fever

Question 21

What MUST you do with bacterial arthritis?

Answer 21

ASPIRATE because bacterial arthritis will generally have purulent synovial fluid.

Question 22

What other lab signs will bacterial arthritis include?

Answer 22

Very low glucose, gram positive in 60-80% of cases

Question 23

What is the most common cause of viral arthritis in the US

Answer 23

Parvo B19

Question 24

Common presentation of Parvo B19

Answer 24

• Slapped cheek

- PIP swelling, MCP swelling, knee, ankle

Question 25

Rubella presentation

Answer 25

Catcher Crouch syndrome

Question 26

Why do children with Viral arthritis due to rubella frequently present with this catcher crouch syndrome>

Answer 26

It is generally due to a lumbar radiculopathy

Question 27

What cause of viral arthritis is generally mosquito borne

Answer 27

alpha virus

Question 28

Lets say a pt shows up at the office and says they had severe and sudden onset of knee pain that went away but was followed by jaundice

Answer 28

This is hepatitis B that caused a viral arthritis. The joint inflammation, generally in the knee, will be explosive but will go away when the jaundice arrives

Question 29

Traditional presentation of hepatitis C arthritis

Answer 29

polyarthritis of small joints (hands, wrists, knees)

Question 30

What bacteria causes lyme dz

Answer 30

Borrelia burgdorferi

Question 31

Classic presentation of lyme dz

Answer 31

B- Bells palsy (sub acute)
A- MigrAtory polyArthritis
K- Heart dz (AV block)
E- Erythema migrans (bullseye)
D- doxy treatment

Question 32

When does teh arthritis associated with lyme dz occur?

Answer 32

months to years after the tick bite and initial infection

Question 33

How do you characterize the effusions associated with lyme dz?

Answer 33

Large effusions typically with little pain

Question 34

Predominant immune response in lyme dz

Answer 34

TH1

Question 35

Rheumatic fever is what type of infection?

Answer 35

Group A strep

Question 36

What is the jones criteria for rheumaoid arthritis?

Answer 36

joint pain
O- carditis, O my heart
N- Sub q nodules
E- erythema marginatum
S- S. Chorea

Question 37

If there is a sudden, explosive arthritis what should you do

Answer 37

Screen for HIV

Question 38

DILS is what

Answer 38

Diffuse Infiltrative Lymphocytosis Syndrome

Question 39

DILS only appears in what kinds of pts

Answer 39

HIV

Question 40

DILS is characterized by?

Answer 40

Gland enlargement: salivary, lacrimal and parotid

CDB involvement. It looks a hell of a lot like sjrogens but it aint. Sjogrens is only CD$ involvement