exam 3 integument part 2 Flashcards
true or false
Edema – Erythema – +/- pustules, crust, vesicles are all forms of late dermatitis
false
early
true or false
Scaling – Change in oiliness – Ulceration – Alopecia – Lichenification – Pigmentary change – Fibrosis/scarring are features of late dermatitis
true
“pus in the skin” – usually bacterial infection involved • Superficial – epidermis and hair follicles – Disease examples • Canine superficial spreading pyoderma / Bacterial folliculitis • Impetigo (superficial pustular dermatitis) • Greasy pig disease • Dermatophilosis • Deep – deep dermis – Disease examples • Bacterial furunculosis • Abscesses
pyoderma
a superficial pyoderma with bacterial folliculitis
Dog with chin acne, a deep pyoderma with bacterial furunculosis
Pores (follicular openings) • Hematogenous spread • Direct entry through damaged skin
how bacteria gets in
predisposing factors of supporative dermitits
Disorders of keratinization (seborrhea) – Endocrine disease – Chronic dermatitis – allergy, parasites, etc… • Immunodeficiency • Anatomic predisposition
why is supporative dermitits more common in dogs
Thin stratum corneum, lack of lipid seal of hair follicles, high skin pH
(Superficial pustular dermatitis) • Nonfollicular pustules which develop into crusts • Prepubescent puppies – healthy otherwise • Adults – look for underlying disease
Impetigo
puppy bellies can get ____
Impetigo
Skin fold pyoderma • Pathogenesis: closely apposed skin surfaces → frictional trauma → moisture → opportunistic bacterial infections
Intertrigo
Pathogenesis: – Self trauma bacterial infection – Underlying pruritis – especially flea allergy dermatitis! • Gross: Moist, alopecic, slightly raised, red well-circumscribed lesions ulceration/crusting
Pyotraumatic Dermatitis (“Hot Spots”) • Very common in dogs
Fatal in neonatal pigs • Caused by Staphylococcus hyicus • Gross: erythema pustules crusts • Predisposing factors – other skin lesions, poor nutrition/husbandry, lacerations
Greasy Pig Disease (Exudative Epidermitis)
train tracks gram positive filamentous bacteria which subdivide longitudinally and transversely • Lesions on back or distal extremities • Stimulate neutrophilic exocytosis: pustules exudate matting of hair/wool alopecia • Predisposing factors – Wet weather in humid climates (“rain rot”) – prolonged wetting of skin/hair/wool allows penetration of epidermis by “zoospores
Dermatophilosis • Caused by Dermatophilus congolensis
‘lumpy wool’ in sheep
Dermatophilosis
Usually secondary condition • Bacterial infection of superficial follicles and adjacent skin • Gross: scaling, erythematous macules (often circular ring shaped), papules, pustules, crusts, epidermal collarettes, alopecia
Canine superficial spreading pyoderma
Folliculitis and furunculosis,
Demodicosis • Cause: Demodex spp. mite
MDx: multifocal exudative dermatitis. Generalized demodicosis with pyoderma in an adult dog
MDx: neutrophilic dermatitis/folliculitis with intrafollicular mites and bacteria.
Dermatophytosis • Cause: Epidermophyton, Microsporum, and Trichophyton spp. (keratinophilic fungi) • Contagious – acquired by contact with scales shed from infected animals • Colonize keratin, do not need to invade tissue to cause disease • Self-limiting in healthy animals, can become chronic/generalized in immunocompromised animals • Predisposing factors – Young or immunosuppressed – Hot/humid environments
Dermatophytosis
Pemphigus foliaceous
Pemphigus foliaceous
