SSTI Part 1 Flashcards
MRSA is resistant to all _______ antibiotics, except for _______.
Beta-lactam; ceftaroline
Why is MRSA methicillin resistant?
It harbors the mecA gene, which encodes PBP2a
PBP2 is the usual target on staph aureus; drugs bind to PBP2a with less affinity so they’re less effective
What are the risk factors for SSTI?
Injury Obesity Poor hygiene Diabetes Vascular disease Immune deficiency Steroids Problems with venous/lymphatic drainage IV drug use
What is Folliculitis? What are the likely pathogens?
Inflammation of the hair follicle, limited to the epidermis
Pruritic, erythematous papules
Likely pathogens: Staph aureus, P aeruginosa (hot tub folliculitis)
How do you treat Folliculitis?
Moist, heated compress
Topical therapy: Clindamycin, Mupirocin, Benzoyl perxocide
What are the types of purulent SSTI’s?
Cutaneous abscess: Collection of pus within the dermis and deeper layers
Furuncle: Abscess originating in hair follice, extended through dermis
Carbuncle: Adjacent furuncles
How do you treat purulent SSTI’s?
1: I & D
#2: Antibiotics, but only sometimes:
When there are systemic signs of infection
Immunosuppressed patients
Multiple/extensive abscesses
Extremes of aging (young and old)
Non-response to I&D (infection still strong after I&D)
C&S is generally recommended
Treatment options for purulent SSTI’s?
Empiric MRSA coverage!
Mild to moderate: Doxycycline/minocycline or TMP/SMX
Severe or immunocompromised patients: Vancomycin IV, goal trough 10-15 mcg/mL if not bacteremic
Duration: 5-10 days
What is Impetigo? Likely pathogens?
Superficial skin infection caused by S aureus or B-hemolytic streptococci
Usually occurs in children, on the face
Most common in the summer and it is contagious
How to treat Impetigo?
Treat for staph and strep unless only streptococci grow in the culture
Topical: Mupirocin or retapamulin BID for 5 days
Oral therapy: Preferred if there are multiple lesions or in an outbreak setting
Dicloxacillin or cephalexin for 7 days (usually MSSA)
If pt has a penicillin allergy, use Clindamycin
What is Lymphangitis? Most likely pathogen?
Inflammation of subcutaneous lymphatic system
Usually occurs secondary to puncture wounds or other skin lesions
S pyogenes most common
Treatment for Lymphangitis?
Initial therapy with IV penicillin G 2-4 million units every 4-6 hours for 48-72 hours
Step down to penicillin VK oral therapy
If they have a penicillin allergy, use clindamycin
Total duration: 7-10 days
Also elevate the affected extremity and soak in warm water every 2-4 hours
What is Erysipelas? Most likely pathogen?
Infection of superficial skin and lymphatic system
Painful, bright red, indurated, raised and well demarcated borders
Almost always caused by B-hemolytic strep, S pyogenes is the most common
What cultures do you get for Erysipelas?
Generally nothing to culture
Get blood cultures if there are severe systemic symptoms, patient is immunocompromised, and there are unusual pre-disposing factors such as animal bites or water immersion
Treatment for Erysipelas?
Penicillin is the drug of choice:
Penicillin G 2-4 million units IV q4-6h
Penicillin VK 500 mg PO QID
If they have a penicillin allergy, just clindamycin
Duration: 5-10 days
