Lecture 13 3/24/25

Question 1

How do autoimmune vs immune-mediated conditions compare?

Answer 1

-both categories see the immune system mistakenly attacking bodily tissues
-autoimmune conditions have identified target antigens
-immune-mediated conditions do not have specific identified target antigens

Question 2

What are the layers of the epidermis?

Answer 2

-stratum corneum
-stratum granulosum
-stratum spinosum
-stratum basale

Question 3

Where are melanocytes found?

Answer 3

stratum basale of the epidermis

Question 4

Which structures are found in the dermis?

Answer 4

-sebaceous glands
-hair follicles

Question 5

Which structure is found in the hypodermis?

Answer 5

cutaneous plexus, containing artery and vein

Question 6

What is the purpose of desmosomes?

Answer 6

to link keratinocyte to keratinocyte

Question 7

What is the purpose of hemidesmosomes and anchoring fibers?

Answer 7

to link epidermis and dermis

Question 8

What is the pathomechanism of pemphigus complex?

Answer 8

breakdown of the epidermal intercellular desmosomal connections

Question 9

What finding is seen in histopath. in pemphigus complex?

Answer 9

separation of keratinocytes in the stratum granulosum

Question 10

Which superficial lesions are seen in pemphigus complex?

Answer 10

-pustule
-crust
-erosion

Question 11

What are the variants of pemphigus?

Answer 11

-pemphigus foliaceus: most common
-pemphigus vulgaris: severe clinical signs and mucosal involvement
-pemphigus erythematosus: PF + lupus histologically
-drug-induced PF: triggered by flea meds

Question 12

Which lesions are seen in pemphigus foliaceous in dogs?

Answer 12

-pustules**
-yellow crusts**
-erosion
*may be pruritic

Question 13

What is the distribution of lesions in pemphigus foliaceous in dogs?

Answer 13

-bilateral symmetry
-nasal planum
-nasal bridge
-periocular area
-concave aspect of ears
-footpads

Question 14

Which lesions are seen in pemphigus foliaceous in cats?

Answer 14

-crusts
-pustules that rupture easily
-erosion
*may be pruritic

Question 15

What is the distribution of lesions in pemphigus foliaceous in cats?

Answer 15

-bilateral symmetry
-face
-ears
-claw folds
-footpads
-around nipples

Question 16

What is the pathomechanism of drug-induced PF?

Answer 16

PF triggered by flea medications and possibly shampoo

Question 17

What is the clinical presentation of drug-induced PF?

Answer 17

-same lesions as regular PF
-lesions begin at the site of medication application
-lesions may expand to the typical PF distribution

Question 18

How is pemphigus complex diagnosed?

Answer 18

-cytology
-histopathology

Question 19

What is seen on cytology that allows for pemphigus complex diagnosis?

Answer 19

-acantholytic cells and neutrophils
-no bacteria (rules out superficial pyoderma)

Question 20

What is the treatment for pemphigus complex?

Answer 20

lifelong immunosuppression and treatment of relapses

Question 21

What is seen when bacteria causes acantholysis?

Answer 21

-pustule lesions
-acantholytic cells + neutrophils with bacteria

Question 22

What is the pathomechanism of autoimmune subepidermal blistering diseases?

Answer 22

autoantibodies against components of the basement membrane

Question 23

What are the deeper lesions seen in autoimmune subepidermal blistering diseases?

Answer 23

-vesicles/bullae with fluid only; no pus
-deep erosions/ulcers

Question 24

What are the types of autoimmune subepidermal blistering diseases?

Answer 24

-mucous membrane pemphigoid: most common, seen at the mucosa of GSDs
-bullous pemphigoid: occurs on haired skin
-epidermolysis bullosa acquisita: seen on the footpads, ears, and oral cavity of young great danes

Question 25

How are autoimmune subepidermal blistering diseases diagnosed?

Answer 25

-histopath. with subepidermal clefting -signalment and clinical distribution to determine variant

Question 26

What is the treatment for autoimmune subepidermal blistering diseases?

Answer 26

immunosuppression

Question 27

What are the categories of lupus-specific skin disease/cutaneous lupus erythematosus?

Answer 27

-subacute CLE -chronic CLE

Question 28

What is the subtype of subacute CLE?

Answer 28

vesicular CLE

Question 29

What are the subtypes of chronic CLE?

Answer 29

-exfoliative CLE -mucocutaneous LE -discoid LE; facial or generalized

Question 30

What are the lupus-nonspecific skin diseases?

Answer 30

-vasculitis -autoimmune BM disease

Question 31

What is the pathomechanism of cutaneous lupus erythematosus?

Answer 31

-UV-induced skin injury -autoantigen stimulation -dysregulation in cell death and clearance processes of basal cells by cytotoxic T cells

Question 32

Which lesions are seen in cutaneous lupus erythematosus?

Answer 32

-ulcer -depigmentation -scarring

Question 33

What are the characteristics of vesicular CLE?

Answer 33

-seen in shelties and collies -found on unhaired skin

Question 34

What are the characteristics of facial-dominant discoid LE?

Answer 34

-most common -seen in GSDs -only occurs on the nose

Question 35

What are the characteristics of generalized DLE?

Answer 35

-annular to polycyclic lesions -found on haired skin

Question 36

Where is mucocutaneous CLE found?

Answer 36

lips and genitalia

Question 37

What are the characteristics of exfoliative CLE?

Answer 37

-autosomal recessive disorder -seen in german short-haired pointers

Question 38

How is CLE diagnosed?

Answer 38

-histopath. with lupus patterns -signalment + clinical distribution to determine variant

Question 39

What are the lupus patterns seen on histopath?

Answer 39

-lymphocyte-rich interface dermatitis -basal keratinocyte apoptosis -pigmentary incontinence -lupus band/deposition of immunoglobulins

Question 40

What is the treatment for CLE?

Answer 40

-avoidance of UV exposure -topical and systemic immunosuppression