Soft Tissue Infections

Question 1

An infection of the epidermis usually caused by S aureus and Beta-hemolytic strep

Answer 1

Impetigo

Question 2

Impetigo skin findings

Answer 2

Vesicles, honey-colored crust

Question 3

Impetigo treatment

Answer 3

Limited infections: topical mupirocin or retapamulin

Extensive infx: dicloxacillin (penicillin) or cephalexin (1st gen cephalosposin)

MRSA: Bactrim or doxycycline

Question 4

Infection of the upper dermis, usually caused by Beta-hemolytic strep or rarely by S aureus

Answer 4

Erysepelas

Question 5

Erysipelas skin findings

Answer 5

well-demarcated, edematous area of erythema, often on the face. Painful

Can have fever

Question 6

Erysipelas treatment

Answer 6

First line: penicillin

If S aureus suspected: 1st gen cephalosporin

MRSA: Bactrim or doxycycline

Question 7

Infection of the dermis and subcutaneous fat with possible portal of entry

Answer 7

Cellulitis

Question 8

Cellulitis most common bugs

Answer 8

S aureus
Strep pyogenes

Question 9

Cellulitis - if diabetes present Abx must cover?

Answer 9

Pseudomonas and gram (-) rods

Question 10

Human bite pathogens

Answer 10

anaerobes (Eikenella)

Question 11

Animal bite pathogens

Answer 11

Anaerobes (Pasteurella - cats) (Capnocytophaga - dogs)

Question 12

Cellulitis skin findings

Answer 12

warmth, erythema, tenderness

Possible abscess

Question 13

Cellulitis differential diagnosis

Answer 13

Stasis dermatitis (chronic, bilateral, no systemic symptoms)

Necrotizing fasciitis (pain out of proportion to PE, gas on imaging)

hypersensitivity reactions (hives, pruritic, suspected distribution)

DVT

Question 14

Cellulitis workup

Answer 14

Blood cultures
CBC
ESR, CRP
XR

Question 15

Cellulitis management

Answer 15

First line: 1st gen cephalosporin (cephalexin), penicillin if abscess

MRSA: clindamycin, doxycycline, Bactrim, vancomycin (if inpatient)

Gram (-) coverage if diabetic

Human/animal bites: Amoxicillin/clavulanate (Augmentin) for anaerobes

Tetanus vaccination

If abscess: incision and drainage

Question 16

Rapidly spreading infection of the subcutaneous fat and fascia

Answer 16

Necrotizing fasciitis

Question 17

Necrotizing fasciitis presentation

Answer 17

erythematous, warm, tenderness

Rapidly progresses to dark, indurated skin with bullae

Toxic appearing

Question 18

Necrotizing fasciitis complication

Answer 18

Compartment syndrome due to edema - out of proportion pain, weakness, paresthesia/numbess

Question 19

Necrotizing fasciitis differential

Answer 19

Requires high degree of suspicion

Cellulitis

Can have elevated CK levels

Question 20

Necrotizing fasciitis diagnosis

Answer 20

CT or MRI to look for gas and soft tissue involvement

Question 21

Necrotizing fasciitis treatment

Answer 21

Surgery consult

Fasciotomy needed if compartment syndrome present

Clyndamycin for anti-toxin, vancomycin for MRSA

If mixed infection: Zosyn

Question 22

Necrotizing fasciitis complications

Answer 22

Compartment syndrome

Shock

multiorgan failure

Dearth