9- Microbial causes of skin disease: bacterial Flashcards
Give 2 reasons why bacterial skin disease occurs
Mechanical damage to the skin
Immunocomprimise
Defects in skin barrier function
Changes to skin microclimate
Dysbiosis
Define Dysbiosis
imbalance of the microbes in our skins normal by microbiome that tips over ultimately into clinical disease.
Name the 3 portals of entry for bacteria into the skin
Via follicles
Via damaged skin
Haematogenous spread (rare)
What does disease manifestation depend on in bacterial infections
Depends on Organism and its virulence factors, predisposing/coexisting factors, host immune response
Name the 5 common clinical manifestations of bacterial skin disease
Surface pyoderma
Superficial pyoderma
Deep pyoderma
Bacterial granulomatous dermaitits
Skin lesions secondary to systemic bacterial inf. or infection with toxin producing bacteria
What is surface pyoderma
Where bacteria multiply on the skin surface only
Give an example of surface pyoderma
Canine intertrigo (skin fold)
Acute moist dermatitis (hotspots)
Bacterial overgrowth syndrome
Superficial pyoderma is an infection within what?
Epidermis +/- hair follicle
What clinical signs are generally associated with superficial pyodermas
–>papules/pustules –> crust, epidermal collarettes/scale, follicular plugs, alopecia
What is impetigo
interfollicular infection of the epidermis (between follicles)
What is an Exfoliative superficial pyoderma
infection between layers of stratum corneum
A deep pyoderma is an infection of what
Infection outside epidermis or hair follicle epithelium
What are deep pyodermas generally due to
rupture of hair follicle wall (furunculosis)
penetrating wounds
haematogenous spread (sepsis)
What is deep pyoderma normally associated with?
Thickening of the skin, nodules and draining sinuses
Abscess
Cellultis
Furunculosis
What is cellulitis
suppurative inflammation of the deep subcutaneous tissue
What is bacteria granulomatous dermatitis caused by
Traumatic implantation of saprophytic organism
How are bacterial skin diseases generally diagnosed
Cytology
Culture
Histopathology- skin biopsy
T/F You always need to give antibiotics for an abscess
False- lance and drain
Antibiotics only indicated if pyrexia/ cellultis is involved
except caseous pus of rabbit abscess- requires surgical intervention
List the broad principles of treating bacterial skin diseases
Kill the organism
Enhance body’s defences where possible
Address underlying cause where possible
When should antibiotics be used when treating a bacterial skin disease
Avoid antibiotics and use topical antibacterials wherever possible
Systemic antibiotics needed for deep infections (base on culture and susceptibility test)
describe acute moist dermatitis
acute lesion caused by skin self-trauma
is a surface pyoderma