What are the primary bacterial pathogens of the skin encountered in small animal practice?
S. psuedintermedius, S. schleferi, S. aureus (in decreasing order of prevalence)
What does staphylococci produce that may induce host reactions or protect the organism?
enzymes (like Beta-lactamase proteases) and toxins (Protein A)
What other bacterial isolates can be found in skin infections?
Proteus, pseudomonas, E. coli, and streptococcal organisms
What about bacterial skin infections favors bacterial growth?
Inflammation of the skin leads to microenvironmental changes (increased temperature and humidity)
What predisposing factors are associated with bacterial skin infections?
signalment, anatomic factors, and environmental factors
What do some breeds have that predispose them to bacterial skin infections?
What anatomic factors predispose them to bacterial skin infections?
skin folds and hair coat type
What environmental factors predispose patients to skin infections?
temperature, humidity, frequent swimming by the pet
What is the most common primary underlying cause of bacterial skin infections?
allergies - atopy specifically
What is the second most common primary cause of bacterial skin infections?
endocrinopathies - hypothyroidism (specifically this one) and hyperadrenocorticism
What other primary factors, aside from the top two, are associated with bacterial skin infections?
ectoparasitic infestations, scaling disorders/disorders of cornification, immunodeficiencies, skin trauma or maceration (over hydration)
What lesions are seen in pyoderma?
papules, pustules, epidermal collarettes, erythema, scale/crusts, patchy alopecia, and draining (fistulous) tracts
What is the severity of pruritus in bacterial skin infections?
mild to moderate
What is the classical lesion for superficial folliculitis?
What are the differential diagnoses for pustules?
pyodermma, autoimmune skin diseases, dermatophytosis, eosinophilic dermatitis, sterile pyogranulomatous dermatitis, and panniculitis
What is the goal of specific diagnostics for bacterial skin infections?
they are intended to confirm the presence of a bacterial infection, then define the causative organism, and identify the primary (underlying) condition
What specific diagnostics can be used for diagnosing the type of bacterial skin infection?
dermatologic data base, cytology, culture and susceptibility/sensitivity testing, routine hematology, evaluation of the thyroid gland, immunologic evaluations, and skin biopsies
When is a cytology a key diagnostic tool in bacterial skin infections?
whenever pustules, papules, or draining tracts are present
What type of samples should be used for cytologies in bacterial skin infection cases?
they should be collected from intact lesions, such as a pustule, when possible
When is culture and susceptibility/sensitivity testing indicated?
recurring infections, failure of the patient to respond to traditional treatment, when the only bacteria on cytology are rod-shaped organisms, and deep pyoderma cases
What types of topical treatments can be used to treat bacterial skin infections?
Gels, creams, ointments, sprays, shampoo therapy, wipes, and astringents
What are the types of gels,creams, ointments, sprays that are used to treat bacterial dermatitis?
Benzoyl peroxide, mupriocin, povidine-iodine, chlorhexidine
What is Benzoyl Peroxide available as?
a gel and shampoo
What is the best used concentration of benzyl peroxide?
2.5% solution - higher can cause severe cutaneous irritation
Is benzoyl peroxide bactericidal or bacteristatic and for how long?
bactericidal for up to 48 hours after application
What actions do benzoyl peroxide have?
follicular flushing action, keratolytic, astringent, degreasing, a debriding action and promotes wound healing
What bacteria is Mupriocin effective against?
staphylococci and gram negative bacteria
Is Povidine-iodine bactericidal or bacteristatic?
How is Chlorhexidine available?
as sprays and shampoo
What active ingredients in shampoos are effective in bacterial dermatitis?
Most to least active - benzoyl peroxide, chlorhexidine, povidone-iodine, triclosan, sulfur/salicylic acid