Bacterial Skin Infections

Question 1

Organism that causes acne

Answer 1

Propionibacterium acnes

Question 2

Open comedos

Answer 2

blackheads

Question 3

Closed comedos

Answer 3

whiteheads

Question 4

G (+) obligate anaerobic, nonmotile, pleomorphic rod. Common in normal flora of the sebaceous glands

Answer 4

P. acnes

Question 5

Folliculitis can be caused by:

Answer 5

S. aureus (G+ cocci with coagulase)

P. aeruginosa (G- bacilla w/ VFs pyocyanin/veridn)

Question 6

Hottub folliculitis is caused by

Answer 6

P. aeruginosa

Question 7

Causes impetigo of Bockhart and Stys

Answer 7

S. aureus (G+ cocci w/ coagulase)

Question 8

Impetigo of Bockhart

Answer 8

Beard area, erythema with papules or pustules

Rupture = yellow crust

Question 9

Folliculitis of the eye

Answer 9

Sty

Question 10

Clinical presentation of P. aeruginosa folliculitis

Answer 10

Systemic Sxs: fever, malaise, HA, sore throat, GI due to the LPS/exotixin A

(because it is G-, there is a systemic component)

Question 11

Hot tub folliculitis is usually developed as a result of

Answer 11

poorly chlorinated water

Usu signs in areas occluded by swimwear

Question 12

Enlarged folliculitis eruptions extended to dermis and SQ layers; Larger abscesses

Answer 12

Furnucles

Question 13

Involves several follicles and extends to dermis and SQ layers

Massive inflammation

Answer 13

Carbuncles

Question 14

Primary cause of non-bullous impetigo (pyoderma)

Answer 14

S. aureus

Question 15

This is most frequently seen in preschool-aged kids, exposed areas of the body, and is increased in warm moist weather

Answer 15

Non-bullous impetigo

Question 16

Non-bullous impetigo is easily transmitted by

Answer 16

fomites (towel) self-infecting–can spread to arms, legs, face

Question 17

Intradermal vesicles with exudate- forms thick amber colored adhesive crust

Answer 17

Non-bullous impetigo

Question 18

Bullous impetigo requires

Answer 18

strain to make exfoliation toxin

Question 19

Large superficial thin-walled blisters. They rupture and crust over and are very contagious! This is not a systemic infection

Answer 19

Bullous impetigo

Both the S. aureus and the exfoliation toxin are in the bullae

Question 20

Similar to staph scalded skin syndrome

Answer 20

Bullous impetigo

Question 21

Clinical presentation of cellulitis:

Answer 21

Heat
Erythema
Edema
Tenderness

Question 22

What should you avoid when treating cellulitis

Answer 22

NSAIDS

Question 23

Acute inflammation of SQ connective tissue. There are few microbes present, and it extends to the lower dermis

Answer 23

cellulitis

Question 24

The Sxs of cellulitis are due to

Answer 24

toxins and inflammatory response

Question 25

Cellulitis is usu caused by

Answer 25

S. pyogenes (G+)

Question 26

Does NF response to ABX?

Answer 26

NO

Question 27

Type I NF

Answer 27

mixed infection- aerobe and anaerobe (AGNR) 4-6 isolates

Question 28

Unexplained and increasing pain--then nerve damage = cutaenous anesthesia

Answer 28

NF

Question 29

Putrid odor is a/w which type of NF?

Answer 29

Type I

Question 30

Type 2 NF

Answer 30

'flesh eating' S. pyogenes - monomicrobic - exposure usu not clear

Question 31

Clinical presentation of NF

Answer 31

``` Pain out of proportion to PE. Hard wooden feel Edema & erythema Putrid odor (Type I) Systemic toxicity ```

Question 32

DX of NF

Answer 32

surgical debridement - could gram stain tissue biopsies and exudate - MRI, CT, xray to determine extent

Question 33

Myonecrosis is caused by what organism

Answer 33

C. perfringens

Question 34

G+ bacillus spore former

Answer 34

C. perfringens

Question 35

Clinical presentation of myonecrosis

Answer 35

Sweet mousy smell Sudden onset of pain, pale, bronze appearance, skin becomes tense, tender, crepitant (H2 gas), may develop bullae that are clear, red, blue, purple Fever, tachy, altered mental status

Question 36

Dx Myonecrosis

Answer 36

tissue biopsy shows gram + rods with no PMNs and muscle necrosis imaging for extent

Question 37

Tx of both NF and myonecrosis

Answer 37

HBO therapy--kills the anaerobes