SA Pyoderma Flashcards
Which bacteria are usually involved in pyoderma?
Staph pseudintermedius, staph aureus, s schleiferi, s hycus, gram -ves (ecoli, proteus, pseudomonas)
Hot spot
pyotraumatic dermatitis
How soon after an inciting cause can a hotspot occur?
Within hours
A flat, erosion with an erythrematous halo
Pyotraumatic dermatitis
Skin fold dermatitis
Intertrigo
What is the pathogenesis of intertrigo?
Compromised skin barrier caused by friction between opposing areas, altered microclimate, loss of normal ventilation or accumulation of fluid. Acts as a growth medium.
BOGS
Bacterial overgrowth syndrome - caused by either allergic dermatitis
Common differentials for pruritis, erythematous excoriations with alopecia found on the ventral trunk.
Malassezia, BOGS
What is the most common pathogen associated superficial folliculitis?
Staph pseudintermedius
What types of lesions may be seen with superficial folliculitis?
Pustules, papules progressing to epidermal collarettes, hyperpigmentation and lichenificaiton
Describe the pathogenesis of deep pyoderma
Demodex, foreign bodies and mixed bacterial infections lead to inflammation of the epidermis, follicle rupture and subcutaneous fat leading to haemorrhagic furuncles, nodules plaques and tracts
Describe the pathogenic features of canine atopic dermatitis.
A defective skin barrier, microbial flare factors and hypersensitivity reactions
What are Favrots criteria for CAD?
<3yo, mostly kept indoors, steroid responsive, feat and ear pinnae (not margins or trunk), alesional pruritis
What lesions may be seen in a dog with CAD?
Alopecia, excoriations, pustules, erythema, lichenification
Which of these diagnostic techniques is affected by external factors (age, drugs, host factors)? IDST or ASIS?
IDST
What treatment protocol may be used for a case of CAD?
Treat SBIs, minimise allergen exposure, immune therapy, improve skin barrier, anti-inflammatory (oclatinib, ciclosporin, glucocorticoid, chloramphenamine)
What bacterial species is the most common cause of chronic otitis in the dog?
Pseudomonas aeruginosa
What is the function of a ceruminolytic drug?
Dewax the ear canal, removing excessive cell debris which can act as a bacterial growth medium
Name and describe the action of surfactants
Separates wax from epithelial surface. Eg lanolin, propylene glycol and mineral oils (+warm water)
Name and describe the action of detergents.
Emulsification of excessive cerumen. Eg chlorhexidine, triclosan
Triclosan is most active against which bacterial species?
Gram +ves
Mupirocin is most active against which bacterial species?
Gram +ves and malassezia (good for surface overgrowth)
Which antifungal is commonly used for dermatological cases?
Miconazole
How do acids help with dermatological pathology? Name an example which is commonly used?
They obv decrease surface pH which can inhibit the growth of some pathogens. They are also often keratinolytic and help to dissolve cell debris. Eg salicylic acid and benzoic acid
What agent is metabolised to benzoic acid?
Benzoyl peroxide
Which acidic agent promotes growth of basal epithelium when applied topically?
Salicylic acid
What is the rational behind using alkalising agents in dermatopathology?
They enhance the action of aminoglycocides and fluoroquinolones
What is the rational behind using tris-EDTA for dermatological infections?
They are useful against gram -ves as they dismantle the cell membrane, thereby allowing antimicrobials to act more effectively
Which degreasing agent should NOT be used in the cat?
TAR
What is the mechanism of action of sulphur containing agents?
Keratoplastic, keratolytic, softens the stratum corneum
