Skin and Soft Tissue Infections

Question 1

Laterally spreading infections, such as cellulitis, are usually caused by:

Answer 1

Streptococcus (usually Strep pyogenes, aka Group A streptococcus)

Question 2

Treatment for Group A strep:

Answer 2

Penicillin

Question 3

Cat bites may introduce:

Answer 3

Pasteurella

Question 4

Human bites may introduce:

Answer 4

Eikenella

Question 5

Fresh water trauma may introduce:

Answer 5

Aeromonas

Question 6

Salt water exposure may introduce:

Answer 6

Vibrio vulnificus

Question 7

Focal infections such as boils and other abscesses suggest the presence of:

Answer 7

Staphylococcus

Question 8

If bigger than ___, an abscess should be drained:

Answer 8

1 cm

Question 9

Oral therapy for staph skin infection:

Answer 9

TMP/SMX
Doxycycline
Clindamycin

Question 10

IV therapy for hospitalized staph skin infections:

Answer 10

Vancomycin

Question 11

Treatment for chronic carriage of staph:

Answer 11

Nasal mupirocin

Question 12

Infection of the epidermis:

Answer 12

Impetigo

Question 13

Infection of the dermis:

Answer 13

Erysipelas

Question 14

Infection of the subcutaneous fat:

Answer 14

Cellulitis (significant risk of systemic spread via lymphatics and blood)

Question 15

Infection of the fascia:

Answer 15

Fasciitis

Question 16

Infection of the muscle:

Answer 16

Myositis

Question 17

Infection of hair follicles:

Answer 17

Folliculitis, furuncles, carbuncles

Question 18

Impetigo cause and treatment:

Answer 18

Caused by Strep (usually).
Mild cases treated with mupirocin.
Severe cases treated with cephalexin (+/- TMP/SMX based on the likelihood of Staph).

Question 19

Necrotizing fasciitis cause and treatment:

Answer 19

Caused by Staph or Strep (rarely by gram-negatives).

Antibiotics given with CLINDAMYCIN to slow toxin elaboration.

Question 20

Erysipelas cause and treatment:

Answer 20

Caused by Group A Strep.

Treated with oral penicillin.

Question 21

Nodular skin lesion in a gardener:

Answer 21

Sporotrichosis

Question 22

Nodular skin lesion in someone with aquatic exposures:

Answer 22

Mycobacterium marinum (“fish-tank granuloma”). Presents with lymphangitic spread.

Question 23

Cellulitis not preceded by trauma:

Answer 23

Group A strep

Question 24

Cellulitis preceded by trauma:

Answer 24

Staph aureus

Question 25

Painless eschar with surrounding tissue edema in someone exposed to animal hides or terrorists:

Answer 25

Bacillus anthracis (a gram-negative rod)

Question 26

Lyme disease treatment:

Answer 26

Doxycycline

Question 27

S. aureus toxigenic infections:

Answer 27

Toxic shock syndrome, scalded skin syndrome

Question 28

Cellulitis predisposing factors:

Answer 28

1) trauma (lacerations, penetrating wounds)
2) obesity
3) lower extremity edema
4) chronic venous insufficiency
5) impaired lymphatic drainage
6) other skin lesions (furuncles, ulcers, etc.)

Question 29

Diagnosis of cellulitis:

Answer 29

Clinical. Blood cultures and biopsy are rarely positive.

Question 30

Paronychia causes and treatment:

Answer 30

Usually Staph aureus. Treatment with moist heat and drainage.

Question 31

Folliculitis treatment:

Answer 31

Topical antibiotic therapy:

1) mupirocin
2) polymyxin B-neomycin-bacitracin

Question 32

Puncture wound through sneaker:

Answer 32

Pseudomonas

Question 33

Foul-smelling wound/gas in tissue:

Answer 33

Clostridium perfringens

Question 34

Sacral ulcers:

Answer 34

Polymicrobial (bowel flora, usually).

Question 35

Treatment for human bites:

Answer 35

IV ampicillin/sulbactam

Question 36

Treatment for animal bites:

Answer 36

IV ampicillin/sulbactam or oral amoxicillin/clavulanate

Question 37

Pyomyositis:

Answer 37

Staph aureus