L4: Bacterial Skin Diseases (Marsella)

Question 1

3 types of cutaneous bacteria

Answer 1

(bact. found on surface and in hair follicles)
1) Residents (e.g. S. pseudointermedius) –> MULTIPLY
2) Transients (e.g. E.coli, Proteus) –> Do NOT multiply
3) Pathogens (S. pseudintermedius, S. schleiferi)

Others: Nocardia, Mycobacteria

Question 2

Feline skin flora***

Answer 2

Staph intermedius
***S. aureus: both humans and cats have S. aureus, and MRSA can transfer from cats to humans and become carriers for life
S. simulans
S. epidermidis
S. xylosus
Pasteurella

Question 3

Equine skin flora**

Answer 3

S. aureus**
S. intermedius
Dermatophilus congolensis

luckily, MDR more common in dogs than cats/horses

Question 4

Porcine skin flora

Answer 4

Staph hyicus

Question 5

Defense mechanisms against skin flora

Answer 5

• Physical (hairs, turnover of stratum corneum)
• Chemical (sebum, fatty acids, antimicrobial pectins)
• Immune system (lymphocytes, langerhans cells, keratinocytes, cytokines)
• Microbial (competition from normal skin flora)

Question 6

pyoderma

Answer 6

pus in the skin (bacterial infection within the skin)

• types classified based on DEPTH of infection
• almost always secondary (never idiopathic)

Question 7

classifications of pyoderma

Answer 7

• primary vs. secondary
• site
• pathogen
• DEPTH: surface, superficial, deep

Question 8

chars. of surface pyoderma

Answer 8

• pyotraumatic dermatitis “hot spot” (common, develop quickly, self-induced or underlying problem)
• skin fold pyoderma “intertrigo”
• on stratum corneum
• side of face common site

Question 9

underlying problems of pyotraumatic dermatitis

Answer 9

• flea allergy
• ectoparasites
• allergic skin diseases
• anal sac diseases
• otitis externa
• contact
• ocular

Question 10

Goldens can develop superficial pyoderma in addition to surface pyoderma. why clinically relevant?***

Answer 10

these need to be put on systemic abx, not just topical tx

-can develop folliculitis or furunculosis

Question 11

Tx of pyotraumatic dermatitis

Answer 11

clip/clean area, topical astringents
-break itch cycle: topical or oral glucocorticoids
+/- systemic abx
-ID and correct underlying cause: kill fleas!!

Question 12

furunculosis

Answer 12

condition is caused by infection that affects the hair follicles and causes small abscesses under the skin that are filled with pus.

Question 13

skin/lip/facial/told fold pyodermas examples of:

Answer 13

surface infection

• require long-term management
• keep clean and dry
• ventral neck usually requires systemic tx