Lecture: bacterial skin diseases Flashcards Preview

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Flashcards in Lecture: bacterial skin diseases Deck (70)
1

Bacteria on skin classified into

  • residents
    • multiply
  • transients
    • do not multiply
  • pathogens
    • s. pseudintermedius
    • s. schleiferi

2

Most mild skin infections located in

the inguinal area

3

99.9 % of skin infections in dogs are

bacterial, usually staph

4

species that normally have s. aureus

horses

cats

humans

5

porcine skin flora

staph hyicus

-can be transmitted to people

6

Physical defense mechanisms

  • hairs, turnover of stratum corneum

7

Biggest guns we have

  • fluoroquinalones: baytril

8

Pyoderma

  • Pus in skin (bacterial infection within the skin)

9

Most instances of pyoderma are primary, or secondary?

secondary

10

classifications of pyoderma

  • Primary vs Secondary
  • Site
  • Pathogen
  • Depth
    • surface
    • superficial
    • deep

11

Surface pyoderma

  • pyotraumatic dermatitis (hot spot)
  • Skin fold pyoderma (intertrigo)

12

underlying causes of surface pyoderma

  1. flea allergy
  2. ectoparasites
  3. allergic skin diseases
  4. anal sac diseases
  5. otitis externa
  6. contact
  7. ocular

13

common area for hotspots

  • face
  • rump

14

Folliculities (little red dots) on edge of hot spot = 

must treat with systemic antibiotics

15

Hot spots topical treatment

  • clip area
  • clean area
  • topical astringents (NO CREAMS OR OINTMENTS)
  • break itch cycle (oral pred)
  • +/- systemic AB
  • identify and correct underlying cause

16

Skin fold pyo may be a combo of pathogens

  • yeast
  • bacteria

*do cytology to see if it is yeast in addition to bacteria

17

Steroid admin in sharpes will

shrink skin folds (decreases mucin)

18

low pH is bad for

bacteria

19

skin fold pyo therapy

  • medical 
    • cleaning
    • wipes (50/50 white vinegar and water)
  • surgery

20

superficial pyoderma

  • deeper than surface pyoderma
  • pustules present in stratum corneum or inside hair follicles

21

most common manifestation of bacterial skin infection see in practice

folliculitis

22

impetigo

  • subcorneal pustules in glabrous areas
  • not contagious like in human dz
  • seen in puppies

23

Impetigo dx

  • signalment and clinical signs

24

Impetigo TX

  • Topical therapy
  • Ensure clean environment
  • Severe or persistent cases may need antibiotics

25

Benzo peroxide

  • human products 5-10 %
  • dog products 2.5 %

*human skin greasier than dog skin. Human products will irritate dog skin

26

FOLLICULITIS (TEST QUESTION)

  • Bacteria: staph
  • Deodex
  • Dermatophyte

27

Primary lesions of furunculosis

  • papules
  • pustules
  • Erythematous macules

28

Secondary lesions of furunculosis

  • circular crusts
  • collarettes
  • focal scale
  • alopecia
  • hyperpigmented macules

29

rancid odor and skin disease can be

yeast or staph

30

Distribution of pyoderma is primarily

(ie distribution of staph infections)

  • Truncal 

31

If you suspect demodex do...

  • deep skin scraping
    • if properly done, negative tests can rule out demodex

32

Adult cigar shaped things on skn scrapings

demodex

33

Diagnosis

  • clinical signs
  • always r/o other causes of folliculitis
    • skin scrapings
  • cytology
  • culture
  • biopsy
  • response to Rx

34

Therapy

  • Antiobiotics (3-4 weeks)
  • Topical therapy
  • Identify and correct underlying cause

35

Equine folliculitis

  • staph
  • dermatophilus congolensis

36

Dermatophilosis

  • Gram + aerobic, or facultative anaerobe
  • actinomycete
  • common
  • organisms in crust
  • zoonotic

37

3 imp factors for infection

  • chronic carriers
    • zoospores resist drying at 100 deg C
    • survives in scabs for 42 months
  • moisture, rain, sweating
  • break in skin integrity
    • trauma, ectoparasites

38

secondary effect of dermatophilus

photosensitizing

39

dermatophilosis

DX

  • cytology
    • railroad tracks

40

Dermatophilosis TX

  • Ususally self-limiting
  • remove from rain
  • Topical
    • benzoyl peroxide and chlorahexidine shampoo
  • Systemic
    • AB for minimum of 2 weeks
      • TMP-sulfa (oral)
      • Penicillin (injectible)

41

Things that don't treat dermatophilus

iodine

42

Penicillin doesn't work for....

canine staph

43

Staphylococcal Folliculitis/Furunculosis

  • staph aureus
  • complication of most pruritic diseases
  • no breed, age predilection

44

staphylococcal Folliculitis/Furunculosis

3 main syndromes

  • Trunk
  • Tail
  • Pastern

45

Truncal Folliculitis

(Heat rash, saddle rash)

  • Painful papulonodular eruption
  • Saddle areas & can spread
  • horse may be non-compliant

46

Tail pyoderma

  • pustules in dorsal area of tail
  • induced by tail rubbing
  • pruritic
  • increases self induced trauma

47

Pigs

  • Exudative Epidermitis
    • S. hyicus
    • toxins absorbed: liver and kidney dz
  • Suckling pigs

48

Pigs and crusty dermatitis

  • Mites (pigs often get mites)
    • do cytology and scraping in case you need to treat staph and mites

49

Deep pyoderma

  • Furuncolosis
  • Abscess/cellulitis/panniculitis

50

Furunculosis

  • Hair fllicles rupture and infection spreads to dermis
  • infection may be mixed
  • Need antibiotics so they don't get systemic infection and sepsis

51

Furunculosis

CS

  • Ulcers
  • Fistulous tracts
  • Pustules / Bulla
  • Cellulitis

52

Localized furunculosis

  • can be from demodex
  • can be on face / chin
  • pressure point pyoderma

53

Acral lick dermatitis

  • treat like deep pyo
  • give AB
  • Then look for underlying disease

54

German Shepherds prone to

deep Pyoderma

55

A dog with deep pyoderma

DX

  • R/O Demodex
  • Cytology
  • Culture
  • Biopsy
  • Response to AB

56

length of AB for superficial pyoderma

3-4 weeks

(7-10 days after resolution of clinical signs)

 

57

Dog with lesions on the face, and/or lesions on the feet

ALWAYS HAVE TO SCRAPE

58

Deep pyo TX

  • Antibiotics
  • Topical therapy
  • Underlying cause
  • Immunotherapy
  • AVOID STEROIDS

59

Deep pyo lenth of AB

  • At least 2 months
  • Choice of AB based on CULTURE/SENSITIVITY, cost and safety

60

Try to match your (dx tools)...

Culture with cytology

(always do both)

61

Abscesses

  • Result of trauma/wounds/foreign bodies
  • common in male cats
    • Pasteurella
  • Establish drainage
  • Systemic AB (e.g., Clavamox)

62

Persistent pyo/staph infection

comes back after two weeks

63

Recurrent staphy/pyo

comes back after 2 months

64

Recurrent staph pyo

  • recurrent vs persistent
  • inappropriate therapy
  • look for underlying cause

65

underlying cause of recurrent staph/pyo

  • Demodex
  • Dermatophyte
  • Atopy
  • Endocrine/metabolic
  • Immunodeficiency
  • Physical causes

66

Juvenile Pyoderma (Canine Juvenile Cellulitis) is not really....

 

not really an infection

*aka puppy strangles

67

Juvenile pyo

CS

  • Typically young puppies (sometimes young adults also)
  • Edema: face, lips, pinna
  • Pustules
  • Lymphadenopathy
  • Fever 
  • Depression

68

Top DDX for puppy with swollen face, swollen lymph nodes

  1. Puppy strangles TX: steroids
  2. Demodex TX: do not give steroids

69

about puppy strangles

  1. Idiopathic disease
  2. Not a real infection
  3. Immune-mediated response
  4. rule out demodex

70

Puppy strangles TX

  • Glucocorticoids at high doses
    • prednisone 2-2.2 mg/kg for 7-10 days
    • taper over 3 weeks
    • relapses are possible
  • Common to use AB to cover for secondary infections