SSTIs Flashcards
Normal flora of the face, neck
Staph. epidermis
Normal flora of the axilla and groin
GNRs (acinetobacter spp.)
Primary infections
Usually involve areas of previously healthy skin and are typically caused by one pathogen
Secondary infections
Usually occur in areas of previously damaged skin and are often polymicrobic
cSSTIs
Complicated
Represents the more severe end of all SSTIs
Classification secondary to clinical decision
Impetigo definition
Superficial infection of stratum corneum
Impetigo epidemiology
Children
Poor hygiene
Impetigo causative organisms
S. aureus (including MRSA)
Group A streptococci
Impetigo clinical presentation
Purulent, localized vesicles/lesions
Mild pain, pruritis
Most common on exposed areas
Impetigo topical treatment
Wash affected area w/ soap and water
x 5 days if localized lesions
Mupiricin or Retapamulin
Impetigo oral treatment
Dicloxicillin, keflex, augmentin
If MRSA suspected: Doxy, Clinda, Bactrim
If streptococci alone is isolated: PCN G PO
Erysipelas definition
Cellulitis involving the more superficial layers of the skin and cutaneous lymphatics
Erysipelas epidemiology
Very young and very old
Erysipelas causative organisms
Group A streptococci
Erysipelas clinical presentation
- Raised, erythematous lesions with clear line of demarcation
- Typically associated with intense burning
- Orange peel appearance
- Often with systemic symptoms
- Most commonly affects the lower extremities
Erysipelas treatment
PCN G (any route) or Amoxil x 7-10 days
Purulent SSTIs
Furuncles
Carbuncles
Cutaneous abscess
Furuncles definition
Infection of the hair follicle that usually extends through the dermis into the SQ tissue resulting in small abscess
Carbuncles
Inflammatory nodule that extends through multiple adjacent follicles
Purulent SSTI epidemiology
Irritation/injury to hair follicle/skin
Purulent SSTI causative agent
S. aureus (if MRSA - angry looking w/black spot in the middle)
Furuncle clinical presentation
Inflammatory, draining nodule involving a hair follicle
Lesions start as a firm, tender, red nodule that becomes painful and fluctuant
Lesions often drain spontaneously
Lesions caused by CA-MRSA often have necrotic centers characteristic of “spider bites”
Carbuncle clinical presentation
Form broad, swollen, erythematous, deep, and painful follicular masses
Commonly develop on the back of the neck and are more likely to occur in patients with diabetes
General treatment of Purulent SSTIs
Incision and drainage, culture/sensitivity testing recommended for all carbuncles, large furuncles and abscesses
Purulent SSTI treatment: Mild infection
Localized; no systemic signs of infection
Mainly small furuncles
ABX not needed
Purulent SSTI treatment: Moderate infection
systemic signs of infection; use PO Rx x 5-10 days Empiric Rx: Bactrim or doxycycline Defined Rx: -MRSA: Bactrim -MSSA: Dicloxacillin/keflex
Purulent SSTI infection: Severe infection
If failed incision/drainage PLUS PO antibiotics, or if systemic inflammatory response syndrome is present; use IV rx x 5-10 days
Empiric Rx: MRSA coverage (Vanc, dapto, linexolid, telovancin, dalbovancin, oritavancin, ceftaroline)
Defined Rx:
-MRSA: same as above
-MSSA: Nafcillin/oxacillin/clindamycin
Cellulitis definition
Involves deeper dermis and SQ fat