Integument Flashcards
What are the three proposed pathogenesis for interface dermatitis?
- Cytotoxic T –cell attack on keratinocytes or melanocytes, or basement membrane components
- Non-immune mediated damage-drugs
- Unknown
moth eaten coat appearance
folliculitis/furunculosis
pyoderm (bacterial infection of the follicles)
What are the three most common organisms that colonize follicles causing folliculitis?***
Name two other cause of folliculitis?
bacteria
dermatophytes
mites
immune mediate or idiopathic
Vesicle
hyperpigmentation from chronic inflammation and hypothyroidism (other option idiopathic)
Type of acanthosis?
hyperplasia with long, irregular and anastomosing rete ridges extending into the dermis. Cells in this type of hyperplasia are still well differentiated and maintain orientation with the basement membrane
Pseudocarcinomatous
What two patterns are observed for vesicular/pustular dermatitis?
A. intraepidermal (subcorneal or suprabasilar)
B. subepidermal (splits epidermis and dermis)
A dog/horse present with edema, cutanous hemorrhage, possible infarction, and sloughing of extremities. What skin disease pattern is likely?
vasculitis
panniculitis
Ichthyosis (marked hyperkeratosis)
SC is sticky and does not exfoliate
What is commonly seen with skin atrophy?
comedones- plug of follicular SC & dried sebum in hair follicle
Erysipelothrix rhusiopathiae septic emboli
vasculitis
collections of fluid & inflammatory cells in the epidermis or subepidermal region.
Pustule
What cells are important components of the skin immune system (SIS)?
langerhan cells, keratinocytes, intr-epidermal lymphocytes, and dermal perivascular unit
punch biopsy margins
3 cm
place in 10x non-buffered formalin
Rabies vaccine associated Vasculitis
(fibrinoid degeneration)
Perivascular dermatitis
atopy
Type of gland:
sweat glands
sebaceous glands
sweat glands- apocrine
sebaceous- holocrine glands
loss of cohesion
between keratinocytes due to
breakdown of cell to cell attachments
acantholysis
What are the adnexa?
hair follicles; sweat, sebaceous, mammary, accessory glands
Ballooning degeneration
viral cytopathic effect
If an animal presents with perivascular dermatitis with eosinophils, it is highly suggestive of what?
hypersensitivity
What are the two sequelae of vasodilation in the skin?
erythema (reddening of the skin)
edema
Describe the location of the vesicles below.
What are the two types of intracellular edema?
hydropic degeneration: affects basal layer, keratinocytes contain vacuoles (lichenoid dermatoses, drug eruptions, dermatomyositis)
ballooning degeneration: swollen eosinophilic keratinocytes in superficial layers of the dermis (viral infection)- can lead to vesicle formation
increase in width of stratum granulosum (increase cells with keratohyalin granules)
hypergranulosis
Two causes for acantholysis?
Common sequelae of acantholysis?
pemphigus (Type II cytotoxic hypersensitivity)
neutrophilic enzyme destruction
vesicle
What are the structures?
Why do they form?
pustules from acantholysis
pemphigus foliaceus
Full or partial thickness necrosis of the epidermis?
full thickness
toxic epidermal necrolysis
What are the secondary lesions that form to the primary pustule lesion?
crusts
Skin disease?
folliculitis/furunculosis
demodecosis
What is the pathogenesis for nodular to difffuse skin disease?
persisitent Ag stimulation incites cell-mediated response
Type of hyperkeratosis?
parakeratotic
superficial necrolytic dermatitis
skin disease?
pemphigus foliaceus
pustules
Type of skin disease pattern?
interface dermatitis (bubbles, depigmentation)
The dog’s nose used to be black.
hypopigmentation- vitiligo (direct damage to melanocytes d/t immunogens on the surface of these cells)
Type of acanthosis?
papillated
erythema
atrophic dermatoses
What is the primary epidermal change?
Secondary?
vesicle
ulcer
(immune-mediated epidermal-dermal separation)
List the 5 follicular changes that can occur?
hyperkeratosis
folliculitis
furunculosis (rupture of follicle)
dysplasia (blue/fawn animals)
atrophy
Name for this skin appearance?
Type of infection commonly associated?
lichenification (thickening of the skin and accentuation of the skin creases d/t acenthosis)
yeast infection
Hydropic degeneration and apoptosis in basal layer of epidermis accompanied by a diffuse band of lymphocytes, plasma cells, +/- macrophages at the dermal: epidermal junction. Pigmentary incontinence and +/- thickening of the basement membrane. May see clefts or vesicles at the dermal: epidermal junction. Further divided into cell-poor and cell-rich lichenoid dermatoses.
interface dermatitis
mild or severe vasculitis?
mild (alopecia and atrophy)
mild or severe vasculitis?
severe (cuntaneous infarction and ulceration/sloughing)
Interface Dermatitis
lymphoplasmacytic
Discoid lupus (immune attack keratinocytes, thick band of cells at D-E jxn)
What condition results in interface dermatitis that is cell poor and is associated with vasculopathy-ischemia?
familiar canine dermatomyositis
Pathogenesis for vesicle/pustule formation
- Enzymatic destruction
- Immune destruction- acantholysis or other
- Mechanical destruction – burn, friction
- Genetic structural defects
- Marked spongiosis, hydropic or ballooning degeneration
Skin Disease?
nodular to diffuse dermatitis
Major functions of the skin?
- Temp & and blood pressure regulation
- Fluid regulation
- Protection- barrier to the outside world
- Sensation
- Nutrient metabolism
- Immune functions: SIS
Conditions associated with nodular to diffuse skin disease
folliculitis/furunculosis