Flashcards in skin infections 2 Deck (11):
(crusted skin): Classic, nonbullous impetigo = impetigo contagiosa = epidemic
impetigo primarily caused by ??
(GAS) OR BOTH.
classic impetigo epi:
how does it infect??
contagious or not??
what happens in adults??
Peak incidence is in children 2 to 5 years.
Often secondarily infect varicella lesions or lesions present in systemic diseases, such as diabetes mellitus and AIDS and causes scarring.
*Contagious!* Can be passed by fomites. Autoinoculation often causes spread to surrounding areas.
Adults more than children are at increased risk for complications, especially post-streptococcal acute glomerulonephritis (PGN-GAS)
In the superficial epidermis, purulent discharge drying on top of the lesion results in a thickened amber/honey colored adhesive crust that resolves in a couple of weeks without scarring.
Common Factors Predisposing to Impetigo
Anything that causes scratching
epidemic impetigo secondary to ??
shingles: stops along midline
Mupirocin: Impetigo involving limited areas: (topical) Unfortunately, S aureus and MRSA resistance to mupirocin
Retapamulin: New class of topicals/localized impetigo caused by S. pyogenes and MRSA
– Spectrum of retapamulin also includes erythromycin- resistant S. pyogenes, fusidic acid–resistant and mupirocin- resistant S. aureus, and MRSA (including P-VL–positive strains)
• Perform “D-zone test” on all erythromycin-resistant, clindamycin- sensitive strains to identify strains with inducible resistance to clindamycin
if impetigo extends deeper??
Deep type of nonbullous impetigo extending into the dermis ("punched out ulcers" with a greenish-yellow crust and violaceous margin, often
ecthyma mostly caused by ??
occurs where ??
*More commonly caused by GAS* (so worry about sequelae)
Frequently occurs on legs.
Scarring can occur.
Gs/Cx to dx Staph from GAS
can also measure anti-teichoic acid Abs