Skin Infections

Question 1

Causative gram positive bacteria in folliculitis

Answer 1

staphylococcus aureus
-most common cause
-usually on scalp and face

MRSA
-most commonly on the chest, flank, scrotum, periumbilical

Question 2

Causative gram negative bacteria in folliculitis

Answer 2

pseudomonas folliculitis
-known as “hot tub folliculitis”
-attributed to contact with water contaminated with pseudomonas
-eruption begins 8-48 hours after exposure on the trunk and buttocks (bathing suit distribution)

Question 3

treatment of gram positive bacterial folliculitis

(mild)

(extensive)

(suspicion for MRSA)

Answer 3

Mild:
-mupirocin
-clindamycin
-antibacterial cleanser (BP, hibiclens)

Extensive:
-PO abx guided by sensitivity culture

MRSA:
-clindamycin 300mg every 6-8 hours for 10-14 days
-doxycycline 100mg BID 7-10 days
-bactrim BID for 7-14 days
-consider nasal decolonization with mupirocin BID for 5 days

Question 4

treatment of gram negative bacterial folliculitis

Answer 4

-often self limiting without tx

-ciprofloxacin 250-750mg BID in severe or immunocompromised cases

Question 5

which bacteria most commonly causes furuncles and carbuncles?

Answer 5

s. aureus (both MRSA and MSSA)

Question 5

What is the difference between a furuncle and a carbuncle?

Answer 5

a furuncle is a deep infection of the hair follicle

a carbuncle is multiple furuncles coalescing with areas of multiple sinus tracts

Question 6

non-pharm treatment of furuncle/carbuncle

Answer 6

-I&D
-warm compresses
-antiseptic washes

Question 7

treatment of non-purulent cellulitis

Answer 7

Dicloxacillin
Augmentin
Cephalexin
PCN

true PCN allergy: clindamycin

Question 8

treatment of purulent cellulitis (MSSA)

Answer 8

Dicloxacillin
Cephalexin

Question 9

Pathophysiology of necrotizing fasciitis

Answer 9

toxins produced by infectious organisms cause blood vessel occlusion leading to tissue necrosis

Question 10

treatment of purulent cellulitis (MRSA)

Answer 10

Doxycycline
Clindamycin
Bactrim

Question 11

type 1 necrotizing fasciitis

Answer 11

most common

polymicrobial (both aerobes and anaerobes)

associated with abdominal / bowel surgery

Question 12

type 2 necrotizing fasciitis

Answer 12

monomicrobial

Question 13

Necrotizing Fasciitis S&S

N
N
E
C
C
R
O

Answer 13

Numbness (late)

Necrosis

Early extreme pain

Crepitus

Constitutional symptoms

Rapid

Ominous

Question 14

treatment of staphylococcal scalded skin syndrome

Answer 14

systemic abx

usually hospitalization

MSSA: Nafcillin or Oxacillin

MRSA: Vancomycin