Term
| What are host factors of the skin? |
|
Definition
- Surface is dry, not conducive to growth
- Renewal of epidermidis
- Sebaceous secretion - FFA
**disruption by puncture or abrasion, DIABETES |
|
|
Term
| What factors predispose for skin infections? |
|
Definition
- High bacteria conc
- Excessive moisture
- Inadequate blood supply
- Presence of bacterial nutrients
- Corneal layer disruption |
|
|
Term
| What pathogens cause soft tissue infections? |
|
Definition
- S. Aureus and S. pyogenes are the majority
- May be MRSA
- P. Aerug
- Enterococci or E. coli
*** Usually gram(+)!! |
|
|
Term
| What are primary infections? |
|
Definition
Not caused by underlying disease or deep wounds:
- Erysipelas - S. pyogenes
- Impetigo - S. aureus, S. pyogenes
- Cellulitis - S. pyogenes
- Necrotizing fasciitis - 2 types
* Type I - Anaerobes
* Type II - S. pyogenes |
|
|
Term
| What are the 2 types of skin infections? |
|
Definition
- Uncomplicated - Superficial, usually gram(+) - cellulitis, impetigo, abcess, furuncles
- Complicated - gram(+) or (-) - ulcers, fasciitis, Cellulitis, or gangrene |
|
|
Term
| How is MSSA-caused skin infections treated? |
|
Definition
| 1st choice - Nafcillin or a 1st gen Cef (Cephalexin or Cefazolin) Can also use Clinda, Diclox, or bactrim |
|
|
Term
| What are treatment options for MRSA-caused skin infections? |
|
Definition
- Standard: Vancomycin
- Linezolid - serotonin syndrome, platelets, optic neuropathy
- Daptomycin/Cubicin - Causes Rhabdo!
- Tigecycline/Tigracil - A static drug
- Ceftaroline - no Pseudomonal activity |
|
|
Term
| How is Community acquired MRSA skin infection treated? |
|
Definition
| Reserve newer antibiotics for deep seated infections - go with bactrim or tetras |
|
|
Term
| What is the best way to treat decolonized MRSA? |
|
Definition
| Mupirocin BID x5 + Chlorhexidine baths |
|
|
Term
|
Definition
An acute infection affecting the epidermis and dermis that can move to the fascia --> abscess, osteomyelitis, septic arthritis, thrombophlebitis
**S. pyogenes, S. aureus, H. influenzae (1-5) |
|
|
Term
| What type of cellulitis often has mixed infection? |
|
Definition
|
|
Term
| How does cellulitis present? |
|
Definition
- Area feels hot and warm
- Lesions - may be extensive
- Fluid gram stain often negative |
|
|
Term
| How is cellulitis treated? |
|
Definition
- Staph - Dicloxillin (mild), Bactrim (moderate), Nafcillin (severe)
- Strep - PCN
- Gram(-) - Cefuroxime
- Polymicrobe - AMG + nafcillin **w/ anaerobes - clinda or metronidazole
**Tx as a staph infection unless documented strep!! |
|
|
Term
| How is MRSA treated for skin infections? |
|
Definition
- Incision and drainage is necessary
- Purulent - Clinda, Bactrim, tetra
- Non-purulent - beta lactam or clinda |
|
|
Term
| What is necrotizing fasciitis? |
|
Definition
A highly lethal soft tissue infection
- Initially hot, no sharp margins
- bullae filled with liquid --> gangrene
**HAVE to do surgical exploration |
|
|
Term
| What are the 2 types of necrotizing fasciitis? |
|
Definition
Type I - after trauma and IVDA - caused by anaerobes
Type II - S. pyogenes, more virulent
**Tx: Clindamycin most effective for type 2. Otherwise broad spectrum |
|
|
Term
| What is clostridial myonecrosis? |
|
Definition
Gas gangrene - involves skeletal muscle
Caused by Clostridium perfringens
**Tx: PCN + clinda + hyperbaric O2 |
|
|
Term
|
Definition
Nonbullous form - most common, caused by S. pyogenes.
Bullous - in kids, S. Aureus
HIGHLY contagious - lesions --> itchy blisters. Diagnosis by culture |
|
|
Term
| What drugs treat impetigo? |
|
Definition
- Dicloxillin, Cephalexin, Cefadroxil, Clinda x7-10 days
- PCN injection
- Mupirocin oint
- Clinda in PCN allergy |
|
|
Term
|
Definition
St. Anthony's fire - in the very young and very old. Lesions bright red w/ edema. Caused by S. pyogenes
**Tx: PCN or clinda |
|
|
Term
| What is folliculitis/furuncles/carbuncles? |
|
Definition
- Folliculitis - Caused by S. aureus or by P. aerug from swimming. Self limiting, can use warm compresses.
- Furuncles - A red nodule spreads to dermis. May need to drain. TX: Diclox or Clinda
- Carbuncles - Extends to subcutaneous, fever. Same tx. |
|
|
Term
| What causes diabetic foot? |
|
Definition
- Neuropathy - absence of pain, dry cracked skin
- Angiopathy/ischemia - ischemia breaks down skin
- Immune defects - impaired phagocytosis = susceptible to infection. Normal humoral |
|
|
Term
| What pathogens are involved in diabetic foot? |
|
Definition
Polymicrobic!
Often has anaerobes
Staph and Strep + gram(-) (E.coli,Klebsiella, proteus, P. aerug) + Anaerobes (Bacteroides) |
|
|
Term
| What is the main complication from diabetic foot? |
|
Definition
|
|
Term
| What should NOT be done when collecting diabetic foot cultures? |
|
Definition
- Culture uninfected lesions
- Obtain culture without first debriding wound
- Obtain culture by swabbing wound
**Has to be deep wound culture |
|
|
Term
| How is diabetic foot empirically treated? |
|
Definition
- Mild - Cephalexin or Augmentin
- Moderate - Ampi/sulbactam or Ertapenem or Imipenem, Vanc for MRSA, Zosyn for Pseudomonas |
|
|
Term
| How are dog bites treated? |
|
Definition
80% of all animal bites - caused by Pasteurella multocida
**Tx with Augmentin, bactrim in PCN allergy.
Cat bites have more risk of osteomyelitis |
|
|
Term
| What is found in human bites? |
|
Definition
Higher risk of infection by strep, staph, Eikenella, Anaerobes
**Aggressive irrigation and debridement - Augmentin, Doxy, diclox, PCN.
**Serious infection: cefoxitin, Ampi/sul, ertapenem
**PCN allergy: Metronidazole or Clinda |
|
|
