Crusting-Scaling and Pigmentary Disorders

Question 1

is crust usually a primary or secondary lesion?

Answer 1

secondary
rarely primary

Question 2

when might you see crust as a primary lesion?

Answer 2

skin/epidermis itself becomes a crust due to necrosis- vasculitis, burns
less common: combination still connected to each other and glutted together by sebum

Question 3

what are the pustular diseases?

Answer 3

pyoderma
pemphigus foliaceus

Question 4

what diseases are associated with follicular casts?

Answer 4

sebaceous adenitis
demodicosis
dermatophytosis

Question 5

what happens in sebaceous adenitis?

Answer 5

inflammatory cells attack sebaceous glands, destroy them

Question 6

what is sebaceous adenitis associated with?

Answer 6

thymoma-associated exfoliative dermatitis- cats
non-thymoma-associated exfoliative dermatitis- cats
leishmaniosis
idiopathic/hereditary

Question 7

which breeds have an autosomal recessive mode of inheritance of sebaceous adenitis?

Answer 7

akitas
poodles

Question 8

is there pruritus associated with sebaceous adenitis?

Answer 8

no- unless secondary pyoderma present

Question 9

when does sebaceous adenitis show up in predisposed breeds?

Answer 9

1-3 years old

Question 10

how can you confirm diagnosis of sebaceous adenitis in biopsy?

Answer 10

nodular perifollicular dermatitis
mural folliculitis
sebaceous gland absence

Question 11

how can you treat sebaceous adenitis?

Answer 11

cyclosporine
topical treatment
vitamin A
steroids alone not effective
apoquel +/- steroids?
cosmetic issue mainly

Question 12

how long is sebaceous adenitis treated?

Answer 12

best clinical response in about 4 months of treatment
usually life-long

Question 13

what is sebaceous adenitis like in cats?

Answer 13

very rare
can be pruritic
mostly in association with exfoliative dermatitis

Question 14

what can cause primary cornification disorders?

Answer 14

ichthyosis
Zn-responsive dermatitis
primary seborrhea

Question 15

what is the goal with management of cornification disorders?

Answer 15

reduce epidermal proliferation and scale formation
enhance desquamation

Question 16

what are the types of anti-seborrheic medications for cornification disorders?

Answer 16

keratolytic
keratoplastic

Question 17

what is the mechanism of action of synthetic retinoids?

Answer 17

act in nuclei
bind to nuclear retinol receptor molecules
modify gene transcription

Question 18

what are the effects of synthetic retinoids?

Answer 18

anti-proliferative
anti-inflammatory
immunomodulatory

Question 19

what is ichthyosis?

Answer 19

group of inherited skin disorders with symptoms that include dry skin, redness, cracking, scales on skin and commonly foot pads

Question 20

what are the clinical signs of canine ichthyosis?

Answer 20

early age
hyperkeratosis
+/- secondary infections
not pruritic unless secondary infection

Question 21

what is the likely cause of golden retriever ichthyosis?

Answer 21

PNPLA1 gene mutation
lipid layer defect
3/15 had clinical signs

Question 22

how can you definitively diagnose ichthyosis?

Answer 22

skin biopsy

Question 23

what are some secondary cornification disorders?

Answer 23

allergy and cheyletiellosis
hypothyroidism
leishmaniosis
T-cell lymphoma

Question 24

what do primary pigmentary disorders affect?

Answer 24

melanocytes/melanin

Question 25

what can be seen on trichoscopy with color dilution alopecia?

Answer 25

melanin clumping and hair shafts damage

Question 26

which animals are predisposed to vitiligo?

Answer 26

young animals

Question 27

which animals are predisposed to lentigo?

Answer 27

young to middle aged animals

Question 28

how can you distinguish between pigmented papilloma and melanocytoma/melanoma?

Answer 28

both palpable/raised melanocytoma is usually single and papilloma are usually multiple

Question 29

where are lesions in uveodermatologic syndrome?

Answer 29

always on face (nose) or head

Question 30

what are the layers of the epidermis?

Answer 30

stratum corneum stratum granulosum stratum spinosum stratum basale

Question 31

what does crust occur secondary to?

Answer 31

ruptured pustule/abscess or leaking pus/sebum with blood secondary to pruritus/self-trauma

Question 32

what does the skin/epidermis itself become a crust due to?

Answer 32

necrosis- vasculitis, burns very adherent to skin

Question 33

what is the crust in sebaceous adenitis and Zn-responsive dermatitis?

Answer 33

thick scales glued together by sebum

Question 34

what is the etiology of sebaceous adenitis?

Answer 34

sebaceous gland development genetic defect results in glands inflammation autoimmune theory: organ-specific cornification defect leading to sebaceous ducts obstruction lipid metabolism defect leading to cornification defect and abnormal sebum secretion

Question 35

what are the clinical signs of sebaceous adenitis?

Answer 35

gradual development of follicular casts and spontaneous hypotrichosis/alopecia no pruritus unless secondary maybe leukoderma lesions on pinnae common

Question 36

what is sebaceous adenitis like in rabbits?

Answer 36

2-7.5 years partial spontaneous alopecia exfoliative dermatitis

Question 37

how can you treat sebaceous adenitis in rabbits?

Answer 37

cyclosporine triglycerides

Question 38

what can cause secondary cornification disorders?

Answer 38

allergy cheyletiellosis malassezia dermatitis leishmaniosis

Question 39

how can you treat cornification disorders?

Answer 39

moisturizing anti-seborrheic drying and degreasing follicle flushing antipruritic antimicrobial antiparasitic immunomodulatory

Question 40

what can you use for moisturizing?

Answer 40

oils propylene glycol urea glycerin lactic acid

Question 41

which anti-seborrheic drugs are both keratolytic and keratoplastic?

Answer 41

sulfur salicylic acid tar: not for cats selenium sulfide: not for cats

Question 42

what can you use to dry/degrease in cornification disorders?

Answer 42

benzoyl peroxide colloidal sulfur aluminum acetate selenium sulfide: not cats tar: not cats

Question 43

what are the three generations of synthetic retinoids?

Answer 43

isotretinoin etretinate, acitretin adapalene, tazarotene

Question 44

what are the side effects of synthetic retinoids?

Answer 44

KCS pruritus GI upset liver damage teratogenicity periosteal calcification

Question 45

what is presentation like of primary seborrhea?

Answer 45

before 1 year cocker spaniels and other breeds cats too

Question 46

how is ichthyosis classified?

Answer 46

mode of inheritance type of histological changes syndromic/non-syndromic lethality

Question 47

how can you treat ichthyosis?

Answer 47

life-long topical moisturizing shampoo/oils systemic retinoids do not breed

Question 48

what are the melanocyte functions in the skin?

Answer 48

pigmentation inflammation and defense

Question 49

which pigmentary disorders are more difficult to diagnose?

Answer 49

pigmented papilloma or melanocytoma T-cell lymphoma DLE leishmaniosis discoid lupus many differentials