19. Skin Pathology Flashcards
define Impetigo. due to what 2 pathogens?
superficial bacterial skin infection
due to S aureus or S pyogenes
Impetigo: how does it present?
erythematous macules that progress to pustules, usually on the face.
ruptured pustules -> dry, crusted, honey colored lesions.
Impetigo: typical patient? contagious?
typically in kids.
very contagious!
Define Cellulitis. due to what organisms?
dermal/subcutaneous infection
usually due to S aureus or S pyogenes
Cellulitis: presentation? risk factors?
Pres: red, tender, swollen rash with fever
Risk: recent surgery, trauma, bug bite (have to get bacteria into the dermis)
Cellulitis may progress to what?
necrotizing fasciitis with necrosis of subcutaneous tissue due to infection with anerobic flesh-eating bacteria.
in that case, production of CO2 -> crepitus
surgical emergency!
Define staph scalded skin syndrome. what organizm?
sloughing of skin with erythamatous rash/fever. significant skin loss.
due to S aureus
How does S aureus cause SSSS?
Exfoliative A and B toxins -> epidermolysis. Stratum granulosum is separated from rest of skin layers and sloughs off.
order of skin layers from surface to base?
Corneum
Lucidum
Granulosum
Spinosum
Basalis
(Californians Like Girls in String Bikinis)
Toxic Epidermal Necrolysis (TEN) is distingished from SSSS how?
level of the skin separation; TEN is much deeper (dermal-epidermal jct)
Define Verruca. due to what virus? common locations?
Wart. flesh-colored papules with rough surface.
Due to HPV infection of keratinocytes. characterized by koilocytic change.
Hands/feet are common locations.
Define Molluscum Contagiosum. due to what?
Firm, pink, umbilicated papules due to pox virus.
Affected keratinocytes show cytoplasmic inclusions (molluscum bodies)
What is this/ in what patients does it usually arise?
Molluscum contagiosum with inclusion bodies in keratinocytes
Affects children; also sexually active adults and immunocompromised.
