Infections of the Skin I (3)

Question 1

What is the inert and impermeable layer of the skin?

Answer 1

stratum corneum

Question 2

What are the chemical barriers to skin?

Answer 2

fatty acids
inorganic salts
transferrins

Question 3

The skin has ______, bacteria and fungi, that is protective

Answer 3

normal flora

Question 4

What are the factors that affect normal flora on the skin?

Answer 4

hydration
general health
physical and chemical environment - salt, transferrin
other bacteria - nutrients, antibiotic production

Question 5

Normal flora is composed of _____ and _____ flora

Answer 5

resident
transient

Question 6

What is resident normal flora?

Answer 6

live and multiply on the skin (obligate parasites)

form a permanent population

cannot be eliminated

normally are harmless

Question 7

What is transient normal flora?

Answer 7

acquired from environment or mucous membranes

most do NOT multiply efficiently on skin - just there

are transient - can be removed or eliminated

may be involved in pathologic processes like coagulase-positive staphylococcus`

Question 8

What is a primary skin infection?

Answer 8

bacteria initiate and cause most of the pathology

Question 9

In primary skin infections, what is dominant?

Answer 9

single bacterial species

Question 10

[Primary/Secondary] skin infections have a characteristic disease pattern evident - consistent disease syndrome

Answer 10

Primary

Question 11

T/F: Antibacterial therapy is effective in primary skin infections

Answer 11

TRUE

Question 12

What are some examples of primary bacterial infections?

Answer 12

greasy pig disease
dermatophilosis

Question 13

Greasy pig disease is a [primary/secondary] infection and is caused by _____

Answer 13

staphycoccus hyicus
primary

Question 14

Dermatophilosis is a [primary/secondary] infection and is caused by _____

Answer 14

primary
dermatophilus congolensis

Question 15

What are secondary bacterial skin infections?

Answer 15

predisposing conditions like viruses, corticosteroid therapy, etc

Question 16

How do you diagnose a bacterial skin infection?

Answer 16

bacterial culture - must distinguish between colonization and infection

Question 17

Identification of primary and secondary infection is useful if you also consider the presence of ______

Answer 17

normal flora

Question 18

What factors do we need to correlate to determine if it is a bacterial infection?

Answer 18

history
clinical signs
bacterial isolates

Question 19

T/F: You can sample an open tract or erosion to sample for bacterial culture

Answer 19

FALSE

Question 20

What are direct smears?

Answer 20

gram’s and wright’s stains

Question 21

What is a gram stain?

Answer 21

number and types bacteria
presumptive ID
initiation of therapy

Question 22

What is wright’s stain?

Answer 22

presence/type inflammatory cell
degenerate neutrophils with bacteria within the cells is indicative of infection

Question 23

What is a pyoderma?

Answer 23

based on skin involvement and depth of infection

distinctions are clinically useful: deeper the lessons, more likely to be a significant problem

Question 24

What are the types of pyoderma?

Answer 24

surface pyoderma

superficial pyoderma

deep pyoderma

Question 25

What layer of the skin does the surface pyoderma cause?

Answer 25

involved epidermis only

Question 26

What is surface pyoderma?

Answer 26

involves epidermis only

often sequelae to self-trauma or allergic skin disease

examples: hot spots, early skin fold dermatitis

Question 27

What does superficial pyoderma involve?

Answer 27

involves skin down to and including intact hair follicles (folliculitis)

Question 28

What is superficial pyoderma?

Answer 28

pustules are present - mini abscesses

often secondary to other diseases (hormonal, metabolic, parasitic)

recurrence is common and long-term management may be difficult

Question 29

What does deep pyoderma involve?

Answer 29

tissues deeper than hair follicles