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Flashcards in 29. Bacterial Infections Deck (40)
1

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

2

What is the causitive agent in this infection?

Often Staph. Aureus. Sometimes Strep. pyogenes

3

IMpetigo HE... What do we expect to see?

Crust in the stratum corneum have lots of neutrophils

4

What happens to the skin in Bullous Impetigo?

Toxins cause blistering... keritinocytes are destroyed

5

Awww.... whats going on with this little nugget?

Scalded Skin Syndrome

6

Agent responsible for this:

How does it cause this?

Staph aureus

exotoxins: Epidermolytic toxin A and Toxin B cause intraepidermal splitting through granular layer

7

What is destroyed froma cellular standpoing in Scalded Skin?

The desmosomes jnxs in the stratum granulosum are destroyed

8

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

9

Describe the expected HE of scalded skin syndrome

Bullae at surface of skin... surface of epidermis and keritinocytes are destroyed. 

10

Pt comes in with diffuse weepy inflammation on the shins. You test it and find its B-hemolytic steptococci.. Dx

Cellulitis (deep pyogenic infection)

11

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)

12

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

13

Causitive agent of Erysipelas

S. pyrogenes

14

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

15

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

16

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

17

What do we notice about the HE of verrucae ?

See infected cells show keratohyaline granules with intracytoplasmic aggregates

18

What is the dominant feature of this HE?

Koilocytosis: cytoplasmic vaculozation of the upper epidermis

19

YUUUCK... what is this? 

Causitive agent?

Condyloma Accuminatum

HSV 6 or 11 most of the time for STD

20

High risk HPV

16, 18, 31, 33

(most are 6 and 11)

21

General charactestics of condyloma accuminatum

single or multiple paplular lesions, pearly, filiform, fungating, cauliflower or plaque like

22

23

Defining feature of condyloma accuminata?

from HPV

See the koiliocytes

24

HSV more common in kids, seen on lips (coldsores or gingivomatitis)

-lesions in group of clear vesicles that heal w/out scarring

HSV1

25

Mom brings her infant to clinic because her daughter had a diffuse rash with bumps all over and now some are blistering. You notice a mix of macules, vesicles and pustules all over. 

Dx?

 

Varicella Zoster Vius

26

You just informed a dad that his daughter has chicken pox. He said he's been giving his daughter meds to help with the pain and that none of the kids touched any of the vesicles, so he doesn't think the other kids will get it.... set him straight on a few points

DO NOT give child Asprin (Reyes) and tell him it spreads via respiratory route so it doesn't matter if they didn't touch them. 

 

27

Woman comes in with a rash on one side that is burning and painful.. Dx?

Herpes Zoster--- shingles

Recurrace of VZV; latent rxn seen in elderly and immunocompromsed

Unilateral distribution

28

Explain the pathology of this virus

Acantholysis of epidermis, see multinucleated keratinocytes with intranuclear inclusions

Perineurial and intraneurial inflammation

29

Notice the large cells that are multinucleated keritinocytes with intranuclear inclusions... what are these and when do we see them

cowdry type A includions seen in HSV

30

Where does acantholysis occur in HSV

acantholysis of epiderms

31

What is this indicative of?

Tzank smear

use to make rapid diagnosis of HSV when taking sample from open vesicle then stain with Giemsa stain. Not as sensitive

32

Cutaneous infection d/t large brick shaped DNA

Molluscum contagiousum

33

Who gets mol.contagiousum and how and where

acquired infection from close contact of eyelids, face, axilla

Children, see in immunosuppresed pts such as HIV

SUPER contagious

Also STD--on penis, vulva, groin

34

Pathology of Molluscum Contagiousum

Inverted nodule... crater like

Eosinophilic cytoplasmic bodies = Hernderso-patterson bodies

35

Very itchy papulovesicular eruption on the hands (other sites are the fingers, penis, umbilicus, waistband and axilla)

Scabies

36

How is scabies contacted and when does it present

From prolounged direct human contact (not really fomites) see the eruption 4 weeks after infestation

37

YOu suspect dermatophytosis infection in pts nail, what test do you perform?

KOH rapid prep-- see branching of septae

38

Common apperance of dermatophytosis

Scaly, erythematous plaques, often annular

39

What stain do we need to identify a dermatophyotosis (tinea) infection in the superfical stratum corneum?

PAS stain; note the fungal elements in the stratum corneum

40

Dx?

Tinea versicolr... superficial infeciton, seen in tropical climates caused by Malassezia globosa

See hyperpigmentation