Exam 1 Flashcards
what is the largest organ in the body
skin
what are the three layers of the skin
epidermis
dermis
panniculus
what are the functions of the skin
protective barrier
regulates temp and blood pressure
produces vit D
sensory organ
stores nutrients
absorptive surface
innate and adaptive immunity
what kind of epithelium is the epidermis
stratified squamous with keratinocytes
how long for renewal in the haired skin
one month
what are the layers of Strat squam
stratum corneum
stratum lucidum (in non haired)
stratum granulosum
stratum spinosum
stratum basale
what is in the stratum spinosum
desmosomes
what cells are in the epidermis
melanocytes
langerhans cells
merkel cells
what are the melanocytes
in the basal layer and then lower s. spinosum
melanin
what are the langerhans cells
bone marrow-derived cells of monocyte-macrophage lineage
antigen presenting cells
merkel cells
neuroendocrine cells in the basal layer
regions of the body with high tactile sensitivity (digits and lips)
likely related to paracrine or autocrine control of keratinocytes or hair follicles
what is the difference between haired and non haired dermal epidermal junction
in non hair there are papillae that confers resistance to shearing
in haired skin, the junction is smooth
basement membrane zone layers
basal cells
basement membrane
dermis
where are the the hemidesmosomes
basal cells
what type of collagen is in the lamina densa
collagen type IV
what are adnexal structures
hair follicles
sebaceous glands
apocrine glands
what are the functions of the panniculus
adipose tissue
flexibility
insulation
shock absorption in footpads
hair cycle
anagen: growing stage
catagen: transitional phase
telogen: resting stage
exogen: old hair shedding
what kind of hair follicles do cattle and horses have
evenly distributed simple follicles
what kind of hair follicles do pigs have
simple follicles in clusters
what kind of hair follicles do dogs, cats, and goats have
compound follicles composed of primary follicles and smaller secondary follicles
what kind of hair follicles do sheep have
simple follicles in hair areas and compound in wool areas
what are sinus hairs
tactile hairs
simple follicles with blood-filled sinus between the inner and outer layers of the dermal shealth
what glands are open into the hair follicles
sebaceous glands
what glands are modified sebaceous glands in the perianal
hepatic (perianal) glands
what sweat glands are open in the superficial part of hair follicles and what species are they common in
apocrine
everything except carnivores and pigs
what sweat glands are directly open in the epidermis and limited to the footpads of dogs and cats
eccrine gland
what are the anal sac glands
apocrine glands
what are the innate immunity host defense of the skin
stratum corneum barrier
macrophages (dendritic cells)
toll signaling pathways
macrophages and neutrophils
what are the players in adaptive immunity of the skin
langerhans
t lymphocytes
b lymphocytes
keratinocytes
what do langerhans’ cells do
ingest and process antigen, migrate to the regional ln to present antigen to waive t lymphocytes
what are the type of t lymphocytes in the skin
CD8: recognize and kill infected cells
CD4 TH1: activate macrophages cell mediate immunity
CD4 TH2 active b lymphocytes, humoral immunity
what do the b lymphocytes in the skin do
secrete immunoglobulin
what do the keratinocytes in the skin
produce cytokines and growth factors up-regulating or down-regulating inflammation and immune responses
what is acantholysis
detachment of epidermal cells, breakdown of intracellular bridges, formation of intraepidermal vesicles
detached within the vesicle are called acantholytic cells
what is acanthosis
increased thickness of the stratum spinosum due to hyperplasia or hypertrophy
what is loss of hair called
alopecia
what is atopy
hypersensitivity state subject to hereditary influences
what is ballooning degeneration
refers to a specific degenerative change in epidermal cells characterized by swollen, pale eosinophilic cytoplasm w/ intracellular edema w/o vacuolation
calcinosis
abnormal deposits of Ca in tissue as in calcinosis cutis and calcinosis circumscripta
what is a callus
exaggerated hyperkeratosis in a localized area over a pressure point
what is comedo
accumulation of keratin and dried sebum in a dilated pilosebaceous orifices
what is a crust
dired exudates on the skin surface, composed of secretion
what is dysplasia in the skin
some abnormality in cell maturation process and morphology or the relationship between cells in epithelial structures
loss of normal stratification of the epidermis has the connotation of possible progression to neoplasia
epidermal collarette
flat to minimally elevated ring of scale that enlarges peripherally
epidermolysis
separation of the epidermis and dermis with the formation of sub epidermal clefts and blisters
eruption
a rapid development of primary lesions of the skin
erythema
redness produced by capillary dilation and congestion
excoriation
superficial linear erosion or ulcer caused by scratching and rubbing
exocytosis
migration of inflammatory cells and/or erythrocytes through the intercellular spaces of the epidermis
exophytic
growing outward from the skin surface
endophytic
growing inward from the skin surface
fissure
deep linear defect from the epidermis to the dermis
folliculitis
inflammation of hair follicles
furuncle
follicular abscess, boil, ruptured folliculitis
hyperkeratosis
thickening of the stratum corneum due to an increased number of keratinized cells
orthokeratosis
a form wherein the nuclei are lost
hypertrichosis
presence of more or less than normal amount of hair
lichenification
thickening of skin with exaggeration of normal markings. consists of acanthuses, hyperkeratosis and dermal fibrosis
lichenoid
grossly refers to flat-topped papules
macule
a flat, circumscribed, alteration in skin color or texture
may be pale hyperpigmented or erythematous
nodule
a large papule >1cm
papule
circumscribed palpable elevation of skin less than 1 cm
parakeratosis
subset of hyperkeratosis with retention of nuclei in keratinized cells
patch
macule greater than 2cm in diameter
plaque
flat-topped nodule
pustule
small circumscribed epidermal or dermal accumulation of purulent exudate
pyoderma
purulent dermatitis
scab
common word for crust
scale
flake of abnormal or compacted cornfield epithelial cells
seborrhea
a functional disturbance of sebaceous glands or of lipid metabolism of the epidermis. accompanied by abnormal keratinization processes
spongiosis
widening of intercellular spaces due to intercellular epidermal edema
vesicle
a small circumscribed elevation of epidermis caused by accumulation of clear fluid within or beneath the epidermis
wheal
sharply circumscribed skin elevation produced by edema of the superficial dermis
what are the pustular diseases
impetigo
superficial spreading pyoderma
what is impetigo
staph intermeidus
exfoliative toxins
young dogs
pustules
papules
superficial spreading pyoderma
dogs
staph intermedius
exfoliative toxin
secondary to canine atopic dermatitis
large erythematous macule with peripheral collarettes
vesicular and bulbous diseases
pemphigus foliaceus
pemphigus vulgaris
pemphigus foliaceus
autoimmune disease
sub corneal or subfranular vesicles
dorsal muzzle, planum nasale
bilaterally symmetrical
what is affected during pemphigus foliaceus
desmocollin 1
desmoglein 1
pemphigus vulgaris
rare and severe
ulcerative autoimmune disease
oral cavity and mucocutaneous junctions
what protein is an autoantibody against in pemphigus vulgaris
demoglein 3
diseases at the interface between dermal and epidermal
cutaneous (discoid) lupus erythematosus
systemic lupus erythematosus
systemic lupus erythematosus
rare multi systemic autoimmune disease
fever, poly arthritis, proteinuria, neutropenia, CNS
erythema, crusting, depigmentation, alopecia
face ears and distal extremities
purebred cats predisposed
cutaneous (discoid) lupus erythematosus
relatively uncommon
restricted to the face particularly the nasal planum
bilaterally symmetrical
depigmentation and scaling
later alopecia and crusting
basal cell vacuolar degeneration and apoptosis
what are necrotizing epidermal diseases
erythema multiforme
toxic epidermal necrolysis
superficial necrolytic dermatitis
burns
erythema multiforme
immune mediated
cytotoxic T cells leading to keratinocyte apoptosis
erythematous macules or slightly elevated papules
ventrum, footpads, pinnae
drug eruption due to penicillins, cephalosporins
toxic epidermal necrolysis
very rare but life threatening
bulbous detachment of epidermis
facial skin, mucocutaneous junctions, footpads, widespread
drug eruption
superficial necrolytic dermatitis
uncommon disorder in dogs
metabolic or hepatic diseases
erosions and thick crusting on and around footpads, mucocutaneous junctions but also in the pinnae, elbows, ventral thorax, scrotum and vulva
strikingly bilaterally symmetrical
French flag look
what is the French flag
crust and parakeratosis
intra and intercellular edema of superficial keratinocytes
hyperplastic basal layer and supra basal keratinocytes
burns
thermal and chemical
full-thickness coagulative necrosis of epidermis and superficial dermis
what are hyper plastic diseases of the epidermis
acral lick dermatitis
malassezia dermatitis
acral lick dermatitis
relatively common in dogs
extremities
persistent licking or chewing
malassezia dermatitis
a yeast overgrowth
erythema, greasy, crusting, alopecia, lichenification
ventral surfaces, pinnae, interdigit
pruritic
epidermal hyperplasia, parakeratosis, lymphocytic and eosinophilic dermatitis
what are perivascular and vascular diseases
hypersensitivity dermatitis
atopic dermatitis
allergic contact dermatitis
septic vasculitis
nodular diseases of the dermis
infectious nodular diseases
non-infectious nodular diseases
what are the causes of folliculitis
superficial bacterial folliculitis
dermatophytosis (ringworm)
demodicosis
insect bite hypersensitivity
most common hypersensitivity in dogs
dorsal lumbosacral, caudomedial aspect
cats have around the neck and can be generalized
culicoides hypersensitivity in horses
usually more than 2 years old
tail base, withers, head
atopic dermatitis
genetically predisposed
percutaneous absorption and inhalation
second most common hypersensitivity
1-3 year old first signs
face, footpads, pinnae, ventrum
allergic contact dermatitis
chemicals
typically hairless skin
septic vasculitis
cutaneous septic and coagulative necrosis
erysipethrix in piggies
infectious nodular diseases
FeLV FIV
actinomycosis and nocardiosis
leprosy
mycobacterial
blast, Histo, coccidioidomycosis
sporotrichosis
cutaneous pythiosis and habronemiasis
feline leprosy
mycobacterium
nodular lesions
acid fast staining
extremities and loves cold temp
equine pythiosis (swamp cancer)
in the southern states
most common along mississippi
fungus in the water that enters open wound
leg is common
habronemiasis
habronema
larva that gets surrounded by eosinofils
penis often affected
feline eosinophilic granuloma complex
rodent ulcer on the lip
eosinophilic collagenolytic granuloma
linear ulcerated granulomas
plasma cell pododermatitis
cat paws with the skin sloughed off
superficial bacterial folliculitis
staph intermedius
number one cause
dermatophytosis (ringworm)
dogs: microsporum canis
cats: m. canis
horses: trichophyton
pigs. M. nanum
cattle: trichophyton
follicular papules
demodicosis
deep folliculitis and furunculosis
demodex canis in dogs
d. cati in cats
what are the diseases of the panniculus
post rabies vaccination
post injection
idiopathic sterile nodular
traumatic
feline pansteatitis
pancreatic panniculitis
post rabies vx panniculitis
relatively common
alopecic macule, no visible inflammation, hyperpigmentation
2-3 months after vx
aluminum adjuvant
ischemic lesions in the dermis
postinjection panniculitis
uncommonly in cats and rarely in dogs
necrotizing and granulomatous panniculitis and deep dermatitis
no follicular atrophy
idiopathic sterile nodular panniculitis
mini daux
multiple SQ nodules, ulcerations and fistulation
traumatic panniculitis
quite common
focal ischemia caused by blunt trauma or chronic pressure
focal firm SQ nodule
lobular fat necrosis with fibrosis
feline pansteatitis
rare
severe deficiency of vit E
exclusive feeding of canned red tuna
pancreatic panniculitis
very rare in dogs and cats
pancreatic neoplasia, pancreatitis
intravascular release of pancreatic enzymes
localized SQ nodules, ulceration
what are the 6 most common canine skin neoplasms
lipoma
sebaceous adenoma
cutaneous histiocytoma
mast cell tumor
hepatoid gland adenoma
soft tissue spindle cell sarcoma
mast cell tumor canine
most common malignant tumor in dogs
cutaneous
boxers
erythematous, alopecia edematous
eosinophils
cutaneous histiocytoma
the most common tumor in young dogs
button tumor
solitary
head and pinnae
langerhans cells
spontaneously regress in most cases
other histiocytic tumors in dogs
reactive histiocytosis
histolytic sarcoma
lipoma
common benign tumor of fat
slow growing
FNA
differential of infiltrative lipoma
sebaceous adenoma
very common in dogs
solitary and frequently multiple
wartlike
less than 1 cm
head, limbs, trunk, eyelids
hepatiod gland adenoma
perianal
modified sebaceous galnd
only in canines
8-13 yo
intact male
androgen influence
differentiate from perianal gland carcinoma
soft tissue spindle cell carcinoma
diverse
fibrosarcoma
nerve health tumor
hermangiopericytoma
papilloma
virus induced
usually resolve spontaneously
virus in the basal layer so must have an entry route
melanocytoma
benign tumor of melanocytes
common in dogs
mid age
hyperpigmentation
what is the general rule with melano—-
haired skin benign
mucocutaneous junctions malignant
melanoma
malignant tumor of melanocyte
common in dogs
older
unpigmanted possible
melan A immunohisto
cutaneous lymphoma
epitheliotropic
T cell origin
30% or more body coverage
immunohistochemistry CD3+
anal sac carcinoma
apocrine gland
uncommon in dogs
female
differential is hepatic gland tumors
hypercalcemia
likes to metastasize
prog poor
hemangioma
benign tumor of blood vessel
common in dogs
slow growing
hemangiosarcoma
malignant tumor of blood vessel
less common in cats
intradermal hemangiosarcoma less agressive
SQ is agressive
hair follicle tumors
mostly benign
what are the 4 most common feline skin neoplasms
squamous cell carcinoma
basal cell tumor
vaccine-associated fibrosarcoma
mast cell tumor
squamous cell carcinoma
sun-damaged skin
white cats
pinnae, eyelids
locally invasive
basal cell tumor
common in cats
siamese
head neck nasal planum
well circumscribed and firm
slow growing
mostly benign
vx associated fibrosarcoma
aggressive with high mortality
inflammation: lymphocytes, plasma cells, macrophages
aluminum in adjuvant
highly recurrent
mast cell tumor in cats
mostly benign
head
few are malignant
most common skin tumors in horses
sarcoid
SCC
Melanoma
papilloma
what are causes of alopecia
congenital anomaly
follicular dysplasia
ischemia
inflammation
hormonal imbalance
seasonal and physiological
pathological and idiopathic growth arrest
congenital alopecia
genetic
sphinx, Chinese crested
cyclical flank alopecia
northern regions
unknown etiology
hair loss in the late fall to early spring
regrowth by late spring
bilateral symmetry
darker hairs
witches feet
color dilution alopecia
hereditary
color-diluted
dobie, daux, dreat dane
plaque with folliculitis
alopecia X
adrenal sex hormone imbalance
pomeranian
plush coated dogs
between 9mo-2yo
slowly progressive, markedly bilateral
starting from friction
hyperpigmentation
postclipping alopecia
lack of hair regrowth
sled dog breeds
prolonged telogen phase
6-12 months
follicular dysplasia on biopsy
traction alopecia
ischemic damage to the follicles
irreversible
telogen effluvium
rare
widespread alopecia
serious illness
hairless telogen–> follicular atrophy
alopecia areata
autoimmune t cells
common in humans
selective and reversible damage to anagen follicles
no visible inflammation
bilateral
post rabies vx panniculitis
common
poodles
rabies antigen in the vascular wall–> vasculitis–> ischemic dermatopathy
2-3 months after vx
revx NOT recommended
demodicosis
d. canis
not contagious
pruritic
mild and self limiting
generalized demodex
severe and life threatening
immunological incompetence
face, legs, trunk, paws
dermatophytosis
microsporum canis
folliculitis
direct contact
usually self limiting
face and forelegs
zoonotic
hypothyroidism
most common endocrinologic skin disease in dogs
bilaterally symmetrical truncal alopecia
friction areas
thyroid is known for stimulating the anagen phase
what is myedema
droopy face
hyperglucocorticoidism
endogenous and iatrogenic
bilaterally symmetrical
comedones, calcinosi cutis
canine Sertoli cell tumor-associated skin disease
male feminizing hormone
cryptorchid
bilaterally symmetrical alopecia in the perineal regions
canine female hyperestrogenism
Cystic ovaries or functional ovarian tumor
Shares many features with Sertoli cell tumor-associated skin disease
Skin changes in about 50% of cases
Thin skin ( >50%)
Fragile skin - easily ripped!!!
English and French Bulldogs
Biopsy
