Bacterial Skin Disease Flashcards
(50 cards)
1
Q
What are the various types of cutaneous bacteria?
A
- Residents (e.g. Staph, Micrococcus)
- they do multiply
- Transients (e.g. E. coli, Proteus mirabilis, P. aeruginosa)
- Do not multiply, competitive with resident bacteria
- Pathogens (e.g. S. pseudintermedius, S. schleiferi)
2
Q
What are the various types of canine and feline skin flora?
A
- Staph pseudintermedius
- Staph aureus
- Pasteurella multocida
- Staph simulans
- Staph epidermis
- Staph xylosus
3
Q
What are the various equine skin flora?
A
- Staph aureus
- Staph pseudintermedius
- Dermatophilus congolensis
4
Q
What is an example of porcine skin flora?
A
Staph hyicus
5
Q
What are the various physical defense mechanisms of the skin?
A
- hairs
- stratum corneum
- lipid envelope
6
Q
What are the various chemical defense mechanisms of the skin?
A
sebum and fatty acids
7
Q
What are the various immune defense mechanisms of the skin?
A
- lymphocytes
- Langerhans cells
- keratinocytes
- cytokines
- AMPs
8
Q
Which normal cutaneous microbe provides microbial defense for the skin by competition?
A
Staph epidermidis
9
Q
Define pyoderma
A
- bacterial infection within the skin
- can be surface, superficial, or deep and primary or secondary
10
Q
What are some examples of surface pyoderma
A
- pyotraumatic dermatitis “hot spot”
- skin fold pyoderma “intertrigo”
11
Q
How do you describe pyotraumatic dermatitis?
A
- common
- thick or long hair
- warm weather
- rapid onset
- self-induced
- underlying problem
12
Q
What are some underlying problems that can lead to pyoderma?
A
- flea allergy
- ectoparasites
- allergic skin dz
- anal sac dz
- otitis externa
- contact
- ocular
13
Q
How do you treat pyotraumatic dermatitis?
A
- Clip and clean area
- Topical astringents and antiseptics
- break the itch cycle
- topical or oral glucocorticoids
- +/- systemic abx
- identify and correct underlying cause
- kill the fleas!
14
Q
What causes skin fold pyoderma?
A
- surface infection
- warm, moist folds
- bacteria
- yeasts
15
Q
How do you treat skin fold pyoderma?
A
- Medical
- cleaning
- wipes
- Surgical
16
Q
Describe superficial pyoderma?
A
- pustules are present in/under the stratum corneum or inside the hair follicles
- e.g. impetigo “puppy pyoderma”, superficial bacterial folliculitis
17
Q
Describe impetigo
A
- subcorneal pustules in glabrous ares
- not contagious like human dz
18
Q
How do you diagnose and treat impetigo?
A
- Dx: signalment and clinical signs
- Tx:
- topical tx
- ensure clean environment
- severe or persistent cases may need systemic abx
19
Q
What things cause folliculitis?
A
- bacteria
- demodex
- dermatophytes
20
Q
What are three examples of primary skin lesions from bactieral skin disease?
A
- papules
- pustules
- erythematous macules
21
Q
What are some secondary lesions that result from bacterial skin diseases?
A
- circular crusts
- epidermal collarettes
- focal scaling
- alopecia
- hyperpigmented macules
22
Q
What is the distribution of pyoderma?
A
- trunk: ventral abdomen
- pruritus is variable - generally present
23
Q
How do you diagnose folliculitis?
A
- C/S
- always R/O other causes
- skin scrapings
- cytology
- culture
- biopsy
- response to rx
24
Q
How do you treat folliculitis?
A
- antibiotics
- appropriate length of tx
- empirical choice or based on culture and sensitivity
- topical tx
- ID and correct underlying cause!
25
What are the organisms that cause equine folliculitis?
* Staphilococcus spp.
* Dermatophilus congolensis
26
What are the clinical presentations of a dermatophilosis infection?
* Strawberry foot rot
* rain scald
* rain rotscald
* rain rot
* lumpy wool
* Streptothricosis
27
Describe dermatophilosis
* Dermatophilosis congolensis
* Gram + aerobic or facultative anaerobe
* Actinomycete
* Common dz, esp during rainy season
* Horses, cattle, sheep, goats
* Dogs
* **potentially zoonotic**
28
What are 3 factors that are important for dermatophilosis to occur?
* Chronic carriers
* zoospores resist drying at 100 deg C
* survives in crusts for 42 months
* Moisture, rain, sweating
* humidity (controversial)
* Break in skin integrity
* trauma, ectoparasites
29
How is dermatophilosis transmitted?
* mechanical transmission
* flies
* contaminated clippers
* normal healthy skin resistant to infection
30
What are the clinical features of dermatophilosis?
* dorsal surfaces of animals
* thick "paintbrush" crusts
* hair easily removed exposing moist pink skin
* green exudate and erosions
* more painful than pruritic
* dry crusts, scale, alopecia
31
How do you diagnose and treat dermatophilosis?
* Dx: clinical features and cytology (railroad tracks)
* Tx:
* self limiting
* remove from rain
* topical
* benzoyl peroxide and chlorohex shampoo
* systemic abx for min of 2 wks
* TMP-Sulfa
* Penicillin
32
Describe Staphylococcal folliculitis/furunculosis
* Staph aureus
* complication of most pruritic dz
* 3 main syndromes:
* trunk
* tail
* pastern
* no breed, age predilection
33
Describe truncal folliculitis
* heat rash, saddle rash
* painful papulonodular eruption
* saddle areas and can spread
34
Describe tail pyoderma
* pustules arise on dorsal area of tail
* induced by tail rubbing
* pruritic
* incr self induced trauma
35
Describe exudative epidermitis
* caused by S. hyicus
* toxins are absorbed
* liver and kidney dz
* in sucking piglets dz is usually confined to individual animals
36
Describe deep pyoderma
* furunculosis
* abscess/cellulitis/panniculitis
37
What is furuncolosis?
* hair follicles rupture and infection spreads to the dermis
* infection may be mixed
38
What are the clinical signs of furunculosis?
* ulcers
* fistulous tracts
* pustules/bulla
* cellulitis
39
How do you diagnose furunculosis?
* r/o demodex
* cytology
* culture
* biopsy
* response to abx
40
How do you treat furunculosis?
* Abx
* appropriate length of tx
* choice based on C&S
* if mult bacteria, address Staph first
* Topical tx
* antibiotic vs antiseptic
* Underlying cause
* allergies, endocrinopathies
* Immunotherapy
* Staphage lysate
* **Avoid steroids if possible**
41
Describe subcutaneous abscesses
* result of trauma/wounds/foreign bodies
* common in male cats
* *Pasteurella multocida*
* establish drainage
* systemic Abx
42
What are some causes of subcutaneous abscesses in dogs?
* bite wound
* abscessed teeth
* foreign bodies
43
How do you treat subcutaneous abscesses?
* drainage
* flush
* antibiotics
44
What antibiotics should be used to treat subcutaneous abscesses in cats?
* penicillin
* amoxicillin/clavulanic acid
45
What are some recurrent or refractory microbes and substances that can cause skin disease?
* Actinobacillus/Actinomyces/Nocardia
* Yersinia pestis
* Mycobacteria spp.
* Anaerobes\*\*
* Fungi
* Foreign bodies
46
Describe atypical mycobacteria
* cause opportunistic infections
* recurrent draining tracts and cellulitis
* more common in humid, warm climates
* _cats are quite susceptible_
* absence of concurrent immunosuprressive dz
* environmental contamination of wounds
47
What is the typical clinical history of an animal with atypical mycobacterial infection?
* chronic non-healing wounds
* +/- hx of previous trauma
* poor response to traditional abx tx
* slowly spreading nodular dermatitis, panniculitis
* **animal is not sick, despite draining lesions**
* +/- lymphadenopathy
48
Describe "Juvenile Pyoderma"/Canine Juvenile Cellulitis and Lymphadenitis/Puppy strangles
* idiopathic dz
* not a real infection
* immune mediated response
* rule out:
* demodex
* infections
49
What are the clinical signs of juvenile pyoderma?
* typically young puppies although it may occur in young adults
* edema - face, lips, pinna
* pustules
* lymphadenopathy
* fever
* depression
50
How do you treat juvenile pyoderma?
* glucocorticoids at high doses
* prednisone 7-10d
* taper over 3 wks
* relapses are possible
* cyclosporine
* common to also use abx to cover for secondary infections
