Skin Infections- Schoenwald Flashcards
What organism is involved in Folliculitis?
Staph>step
What is the tx for folloculitis?
Warm compress
What should be avoided in folliculutis?
Systemic abx
What areas are involved in a furuncle?
Entire hair follicle + surrounding soft tissue
What organism is involved in a furuncle?
Staph aureus
What is the tx for a furuncle?
- I & D + warm compresses
- Trimethoprim/Sulfa (Bactrim)
- Doxy
What organism is involved in a carbuncle?
Staph aureus
What is tx for a carbuncle?
- I & D + systemic abx
- Cefalexin
- Trimetoprim/Sulfa
What is the f/u for a carbuncle?
- 2-3 days then weekly or f/u with PCP 1-3 days after initiating tx
- If lesion is packed, need to come in frequently to change packing
What organism is involved with erysipelas?
B hemolytic strep
How does erysipelas present on the skin?
- Erythema, classically shiny, well demarcated
- Typically on the face/cheek
- Associated with fever, chills
What is the tx for erysipelas?
- Trimethoprim/Sulfa
- Vanco
- Pen VK
What layers of skin are involved in cellulitis?
- epidermis
- dermis
- subcutaneous (connective) tissue
Where on the body does cellulitis typically present?
Lower leg
What organism is involved in cellulitis?
-Gram + cocci
Staph & strep
What is the mc portal of entry of organisms in cellulitis?
Toe fissures or tinea pedis
What abx are good empiric choices for cellulitis in the outpatient setting?
- Doxycycline
2. Trimeth/Sulfa
What is the outpatient f/u for cellulitis?
Few days
What abx are given to the patient if he/she is hospitalized from cellulitis?
- Vanco
- Ceftaroline
When is hospitalization advised for a patient with cellulitis?
When there is red streaking and spreading
What are 6 common antibiotic choices for cellulitis?
- Penicillins
- B lactam inhibitors (amox/clav)
- Cephalosporins (Ceftaroline)
- Sulfa (trimeth/sulfa)
- Tetracyclines
- Vancomycin
Necrotizing fasciitis quickly and progressively destroys subcutaneous fascia/fat but _______ ___________
spares muscle
What organism is usually involved with necrotizing fasciitis?
Group A strep (M protein) but can be S. aureus
What is the tx for necrotizing fasciitis
Emergent surgery
What is fournier’s gangrene?
Rapidly progressing cellulitis/gangrene of penis and scrotum
Are there typically many initial symptoms of fournier’s gangrene?
No- insidious onset with itching and discomfort (perianal)
Why does pain subside in fournier’s gangrene?
Due to necrosis of nerve tissue during progression
What organisms are involved in fournier’s gangrene?
polymicrobial with high likelihood of anaerobic organisms (from GI)
What is the tx for fournier’s gangrene?
-Surgery
-Broad spectrum abx
(vanco, piperacillin/tazo, metronidazole)
What organism is associated with gas gangrene?
Clostridium perferingens
What layers of tissue are involved in gas gangrene?
Subcutaneous fascia, fat, muscle
How can we distinguish necrotizing fasciitis from gas gangrene?
NF spares muscle whereas gas gangrene destroys muscle
What is the cause of gas gangrene?
Traumatic wounds/perforation of bowel
When and where was the first MRSA case identified?
1965 Boston City Hospital
What are the bacterial surface components of S. aureus (4) that make it more aggressive
- Capsular polysaccharide
- Protein A
- Clumping factor
- Fibronectin binding protein
Name 5 extracellular proteins of S. aureus that make it more aggressive
- Coagulase
- Hemolysins
- Enterotoxins
- Toxic-shock syndrome (TSS) toxin
- Exfoliatins
- Panton-Valentine leukocidin (PVL)*
What gene does MRSA have that makes it resistant to methicillin
mecA
What is the marker drug for methicillin resistance?
oxacillin
What are 5 risk factors for MRSA?
- Previous hospital stay
- Prolonged length of stay prior to infection
- Surgical procedure(s)
- Enteral feeding- tube fed
- Prior antibiotic use
What abx are RF for MRSA?
- 3rd gen Cephalosporins (Cephtriaxone)
- Fluroquinolones (cipro, levo)
- Vanco
What is an important toxin in MRSA?
PVL (Panton-Valentine leukocidin)
What could a patient say that may make you think the person has MRSA?
“I have a spider-bite”
Name 4 traditional treatment options for MRSA
- Vanco
- Trimeth/Sulfa
- Tetracyclines
- Clindamycin
Strains carrying what gene can be induced to become clindamycin resistant?
erm
What does a D-test check
D-test: if erythromycin is resistant and clindamycin susceptible then do D-test check to determine if clind is resistant or not
Should you attempt to decolonize all patients with MRSA?
No- just those likely to benefit (healthcare workers)
How would you treat MRSA intranasally?
Topical intranasal mupirocin for 5 days (not more)
What are two characteristics of diabetic foot?
- Polymicrobial infection
- Anaerobes highly likely
What organism is most likely to cause hot tub folliculutis?
Pseudomonas
What is the outpatient tx of hot tub folliculitis?
Cipro & antihistimines
What do you do for a patient that has a dog bite?
- Irrigation
- Does the dog have a rabies vaccination?
- Human rabies immunization
- Tetanus status?
- Possible abx (depending on the situation- most do)
What abx would you use for a dog bite?
- Augmentin
- Ampicillin/Sulbactim
What organism is associated with dog & cat bites?
-Pasteurella multocida
What organism is associated with cat scratch fever?
Bartonella
What is the treatment for cat scratch fever?
Doxy
What organism is associated with mice & rat bite fever?
Streptobacillus
What is the tx for mice & rat bite fever?
Amov/clav
What organism is associated with human bites?
Eikenella corrodens
What is the treatment for human bites?
Amox/clav
What is the tx for yeast cellulitis?
- Fluconazole
- Nystatin powder (want to use something dry because yeast love moist, warm, environments)
What virus strain is responsible for measles?
Paramyxoviridae
What are the “three C’s” symptoms of measles?
Cough, coryza, conjunctivitis
What is the treatment for measles?
Vaccine
Does herpes usually cross the midline?
No it presents as vesicular dermatomal lesions that do not cross the midline (unless it disseminates)
What is the treatment for shingles?
- Antivirals started within 1st 72 hours of onset of vesicles/prodrome
- Acyclovir, famcyclovir, valacyclovir are options
Is Shingrex or Zostavax the more preferable vaccine for shingles?
- Shingrex- series starting at age 50
- Zostavax is going off the market
What is pathopneumonic for measles?
Koplik spots
What type of rash happens in measles?
Maculopapular
