29. Bacterial Infections Flashcards
What is this bacterial infection? Describe it and where it is commonly located
Superficial bacterial infection: Impetigo
Small vesicles that burst–> replaced by thick honey colored crusts
Most in mouth, nose and extremeties
What is the causitive agent in this infection?
Often Staph. Aureus. Sometimes Strep. pyogenes
IMpetigo HE… What do we expect to see?
Crust in the stratum corneum have lots of neutrophils
What happens to the skin in Bullous Impetigo?
Toxins cause blistering… keritinocytes are destroyed
Awww…. whats going on with this little nugget?
Scalded Skin Syndrome
Agent responsible for this:
How does it cause this?
Staph aureus
exotoxins: Epidermolytic toxin A and Toxin B cause intraepidermal splitting through granular layer
What is destroyed froma cellular standpoing in Scalded Skin?
The desmosomes jnxs in the stratum granulosum are destroyed
Baby comes in with tender skin and macular eruption–> they quickly turn into flacid bullae. Its all over the face, neck, trunk and groin. Ddx?
Scalded skin syndrome
good prognosis in kids
may go to septicemia in adults
Describe the expected HE of scalded skin syndrome
Bullae at surface of skin… surface of epidermis and keritinocytes are destroyed.
Pt comes in with diffuse weepy inflammation on the shins. You test it and find its B-hemolytic steptococci.. Dx
Cellulitis (deep pyogenic infection)
Describe Cellulits
Diffuse inflammation of CT of skin and deeper soft tissues
B-hemolytic strep/coagulase + staph
more common on legs with expanding erythema (tender)
Pt presents with sharpy outlined edematous, erythematous and tender plaque with elevated borders. Your attending says this is often seen in the elderly, but more often on the legs. Dx?
Erysipelas
Causitive agent of Erysipelas
S. pyrogenes
Describe what organs systems/vasculature are involved in this.
Erysipelas
Bacterial skin infection involving the upper dermis and superfical cutaneous lymphatics
-sharply outlined edema, erythema, tender, painful plaque
Describe the HE of Eryipselas and how its different then Scalded skin
Both have lots of edema and neutrophils, but this is located deeper in the upper dermis while SSS is more superficial and involves the epidermis/keritinocytes
Pathology of Verrucae (image is verrucae vulgaris)
Epidermal hyperplasia
Koilocytosis (cytoplasmic vaculoization) of upper epidermal layer. See infected cells show keratohyaline granules with intracytoplasmic aggregates