Skin 5 - Infectious Disorders Flashcards
What is impetigo?
Superficial bacterial skin infection
What is impetigo most often due to?
S. aureus or S. pyogenes
Who does impetigo commonly affect?
children
What does impetigo present as?
erythematous macules that progress to pustules, usually on the face; rupture of pustules results in erosions and dry, crusted, honey-colored serum.
What is cellulitis?
It?s a deeper (dermal and subcutaneous) infection, usually due to S. aureus or S. pyogenes
What does cellulitis present as?
a red, tender, swollen rash with fever
What are the risk factors for cellulitis?
They include recent surgery, trauma, or insect bite.
What can cellulitis progress to?
Can progress to necrotizing fasciitis with necrosis of subcutaneous tissues due to infection with anaerobic flesh-eating bacteria
What happens when cellulitis progresses to necrotizing fasciitis?
1) Production of CO2 leads to crepitus. 2) Surgical emergency
What is staphylococcal scaled skin syndrome?
Sloughing of skin with erythematous rash and fever; leads to significant skin loss
What is staphylococcal scaled skin syndrome due to?
S. aureus infection; where there is exfoliative A and B toxins that result in epidermolysis of the stratum granulosum.
How is staphylococcal scaled skin syndrome distinguished histologically from toxic epidermal necrolysis?
by level of skin separation; separation in TEN (toxic epidermal necrolysis) occurs at the dermal-epidermal junction
What is Verruca?
(wart) Flesh-colored papules with a rough surface
What is verruca due to?
HPV infection of keratinocytes;
What is Verruca characterized by?
koilocytic change
