Cornification

Question 1

keratinization

Answer 1

genetic program of keratinocytes in the basal cell layer to mature, die, and produce the stratum corneum

Question 2

cornification

Answer 2

keratinization + formation of lipid interstitium holding the dead keratinocytes together

Question 3

scale

Answer 3

excess stratum corneum (dandruff)

Question 4

crust

Answer 4

scale + blood, serum, micro-organisms, cells, etc

Question 5

stratum basale

Answer 5

keratinocytes undergoing mitosis

Question 6

stratum spinosum

Answer 6

keratinocytes begin to flatten

attached via desmosomes

Question 7

stratum granulosum

Answer 7

production of keratohyalin and lamellar granules

Question 8

keratohyalin

Answer 8

forms corneocytes

keratin + pro-filaggrin

Question 9

lamellar granules

Answer 9

forms interstitium

ceramides, cholesterol, fatty acids

Question 10

stratum corneum

Answer 10

corneocytes + filaggrin and ceramides

Question 11

filaggrin

Answer 11

protein that holds together keratinocytes

deficiency can cause allergic dermatitis in the presence of microorganisms

Question 12

what causes primary scaling/crusting disorders

Answer 12

breed-related
genetic
idiopathic
nutritional
congenital

Question 13

what causes secondary scaling/crusting disorders

Answer 13

parasites
endocrine disorders
infectious
neoplastic

Question 14

seborrhea

Answer 14

breed related scaling and crusting in dogs

affects trunk and pinnae (ceruminous otitis external)

erythema, pruritus, alopecia, rancid odor

Question 15

what breeds are prone to seborrhea

Answer 15

cocker spaniels
persian cats

Question 16

ichthyosis

Answer 16

rare, congenital, hereditary group of diseases leading to inability to properly form the stratum corneum

leads to excessive scale and crust

Question 17

what breeds are prone to canine ichthyosis

Answer 17

norfolk terriers
golden retrievers
american bulldogs
great danes
Russell terriers

Question 18

idiopathic regional cornification

Answer 18

hyperkeratosis and “fronding” of the foot pads and nasal planum

Question 19

sebaceous adenitis

Answer 19

idiopathic granulomatous inflammation of the sebaceous gland leading to scaling and alopecia

can extend into the hair follicle

Question 20

presentation of sebaceous adenitis in short haired dogs

Answer 20

circular regions of alopecia (geographic)

Question 21

presentation of sebaceous adenitis in long haired dogs

Answer 21

entire segments of alopecia, rat tails, follicular casting

Question 22

follicular casting

Answer 22

excess keratin around the hair shaft leading to waxy debris

Question 23

zinc responsive dermatosis

Answer 23

parakeratosis + hyperkeratosis

resolves with zinc supplementation

Question 24

ZRD syndrome I

Answer 24

crusting/scaling of mucocutaneous junctions (eyes, lips), elbows, and foot pads
- bilateral, not symmetrical

common in Siberian Huskies

Question 25

ZRD syndrome II

Answer 25

crusting plaques (dermis and epidermis), fissuring of foot pads, fever, malaise

young dogs fed excess Ca or plant protein

any breeds

Question 26

cattle ZRD

Answer 26

hereditary defect in zinc absorption from GIT

diarrhea, skin lesions, poliosis, decreased suckle reflex
inflammation and crusts around eyes, base of ears, coronary bands, muzzle

Question 27

goats ZRD

Answer 27

caused by alfalfa (high Ca) or over-liming (Ca salts) leading to Zinc deficiency

crusts, bilateral symmetrical alopecia, rough hair coat, abnormal claw growth

Question 28

swine parakeratosis

Answer 28

inadequate intake of zinc or excessive intake of Ca

RARE

thickened, encrusted, and fissured skin, poor growth

Question 29

equine mane and tail seborrhea

Answer 29

scaling and crusting along the mane and tail

Question 30

equine canon keratosis

Answer 30

excess stratum corneum deposited along the distal liumbs

Question 31

equine linear alopecia

Answer 31

vertical lines of non-pruritic, non-painful alopecia

common in quarter horses

Question 32

histology of linear alopecia

Answer 32

lymphocytic to granulomatous mural folliculitis (in follicle wall NOT lumen)

hyperkeratosis