Immune-mediated skin disease

Question 1

what is immune-mediated skin disease?

Answer 1

when the immune system fails to tolerate self-antigen and mounts an immune response to normal skin components

Question 2

what causes primary immune-mediated skin disease?

Answer 2

idiopathic

Question 3

what causes secondary immune-mediated skin disease?

Answer 3

trigger - toxin, drugs, bacteria, virus…

Question 4

what are the key points to look for on an exam of a dog with suspected immune-mediated skin disease?

Answer 4

primary lesions
distribution of lesions
signalment/breed

Question 5

what are the advantages of using cytology for immune-mediated skin disease?

Answer 5

easy, cheap, rapid
determines if sterile or not
determine type of inflammation

Question 6

what are the two main sampling techniques used for cytology of immune-mediated skin disease?

Answer 6

direct impression smear
FNA

Question 7

what lesions is direct impression smears useful for sampling?

Answer 7

pustules, exudative lesions (erosions/ulcers), draining tracts

Question 8

what are skin biopsies and histopathology used for in immune-mediated skin disease cases?

Answer 8

getting a definitive diagnosis

Question 9

what are the key points to remember when taking skin biopsies to use for immune-mediated skin disease diagnosis?

Answer 9

take at least three
sample primary lesions
sample range of lesions
sample entire lesion if possible
avoid erosions/ulcers

Question 10

why are erosions/ulcers avoided when taking skin biopsies?

Answer 10

missing the epidermis so can’t diagnose anything that may be happening in this layer

Question 11

what skin lesions can be seen in immune-mediated skin disease cases?

Answer 11

pustules
plaques/nodules
erythematous macules/patches
hypopigmented macule/patches
alopecia
vesicles
erosions/ulcers
crusts
purpura
scale

Question 12

what are the main primary lesions seen with immune-mediated skin disease?

Answer 12

pustules
plaques/nodules
erythematous macules/patches
hypopigmented macule/patches

Question 13

what are the least helpful lesions when trying to make a differential diagnosis for immune-mediated skin disease?

Answer 13

erosions, ulcers, crusts

Question 14

what are crusts?

Answer 14

dried exudate on skins surface

Question 15

what can crusts form from?

Answer 15

pus from pustules
exudate from ulcers/erosions
blood

Question 16

what is the list of differentials for pustules?

Answer 16

bacterial infection (pyoderma)
pemphigus foliaceus
superficial pustular drug reaction
superficial pustular dermatophytosis

Question 17

what are the two immune-mediated skin diseases that cause pustules?

Answer 17

pemphigus foliaceus
superficial pustular drug reactions

Question 18

what is the lesion distribution for Memphis foliaceus?

Answer 18

footpads, pinnae, muzzle, ocular, lateral flanks

Question 19

what disease are acantholytic keratinocytes seen with?

Answer 19

pemphigus foliaceus

Question 20

why do we get acantholytic keratinocytes with pemphigus foliaceus?

Answer 20

auto-antibodies target desmosomes (these link the keratinocytes in the dermis) and hence the keratinocytes separate and become rounded

Question 21

what do desmosomes do?

Answer 21

link keratinocytes in the dermis

Question 22

what is the most common immune-mediated skin disease of dogs?

Answer 22

pemphigus foliaceus

Question 23

in general how fast of an onset do immune mediated diseases have?

Answer 23

acute onset

Question 24

what age dogs get eosinophilic furunculosis of the face?

Answer 24

young adults

Question 25

is eosinophilic furunculosis of the face pruritic?

Answer 25

yes, very intense

Question 26

what lesions are associated with eosinophilic furunculosis of the face?

Answer 26

eroded/ulcerated plaques and nodules

Question 27

what is folliculitis?

Answer 27

inflammation of hair follicle

Question 28

what is furunculosis?

Answer 28

breakdown/bursting of hair follicle

Question 29

what age dog is sterile granulomatous dermatitis and lymphadenitis?

Answer 29

young puppies (juvenile cellulitis)

Question 30

is sterile granulomatous dermatitis and lymphadenitis pruritic?

Answer 30

no (but is painful)

Question 31

what lesions are seen with sterile granulomatous dermatitis and lymphadenitis?

Answer 31

follicular nodules (furunculosis), plaques, diffuse swelling, alopecia, lymphadenomegaly

Question 32

what is the distribution of sterile granulomatous dermatitis and lymphadenitis lesions?

Answer 32

face (and lymph nodes)

Question 33

what is the prognosis of sterile granulomatous dermatitis and lymphadenitis?

Answer 33

good

Question 34

what is the distribution of sterile nodular panniculitis lesions?

Answer 34

trunk

Question 35

what are the types of cutaneous lupus erythematosus?

Answer 35

vesicular (rapid onset and rare) facial discoid lupus erythematosus (chronic and common) generalised discoid lupus erythematosus (chronic) mucocutaneous lupus erythematosus (chronic) exfoliative cutaneous lupus erythematosus (chronic)

Question 36

what is the most common type of cutaneous lupus erythematosus?

Answer 36

facial discoid lupus erythematosus

Question 37

what breed is predisposed to discoid lupus erythematosus?

Answer 37

German shepherds

Question 38

what lesions are seen with facial discoid lupus erythematosus?

Answer 38

loss of cobblestone appearance of nasal planum hypopigmented macules/patches erosions, ulcers, crusting black to blue to pink pigment change

Question 39

what are the main types of erythema multiforme?

Answer 39

major and minor

Question 40

what disease is target lesions seen in?

Answer 40

erythema multiforme

Question 41

what types of erythema multiforme have target lesions?

Answer 41

minor and major

Question 42

is erythema multiforme pruritic?

Answer 42

no

Question 43

what can trigger erythema multiforme?

Answer 43

virus, drugs, vaccine, infection, neoplasia, food, idiopathic

Question 44

what is the primary lesion of erythema multiforme?

Answer 44

annular erythematous macule (target lesion)

Question 45

what is the distribution of lesions of erythema multiforme?

Answer 45

ventral abdomen (can be generalised mucosa)

Question 46

what type of inflammation is seen on cytology of dogs with erythema multiforme?

Answer 46

sterile non-specific inflammation

Question 47

what is the main finding on histopathology of erythema multiforme?

Answer 47

keratinocyte apoptosis

Question 48

what aged dogs are effected by hyperkeratotic erythema multiforme?

Answer 48

older

Question 49

what breed is predisposed to uveodermatologic syndrome?

Answer 49

akita

Question 50

what aged dogs are effected by uveodermatologic syndrome?

Answer 50

young to middle aged

Question 51

is uveodermatologic syndrome pruritic?

Answer 51

no

Question 52

what lesions do dogs with uveodermatologic syndrome have?

Answer 52

bilateral uveitis hypopigmented macules

Question 53

what is the distribution of uveodermatologic syndrome lesions?

Answer 53

face, nose, lips, periocular skin (occasionally footpads)

Question 54

are disease cause immune-mediated alopecia?

Answer 54

sebaceous adentitis alopecia areata dermatomyositis ischaemic dermatopathy post-injection alopecia

Question 55

what breeds are predisposed to sebaceous adenitis?

Answer 55

poodle, akita, vizsla

Question 56

is sebaceous adenitis pruritic?

Answer 56

no

Question 57

what lesions are seen with sebaceous adenitis?

Answer 57

partial alopecia and poor coat quality follicular casts and scale

Question 58

what is the distribution of sebaceous adenitis lesions?

Answer 58

generalised

Question 59

is alopecia areata pruritic?

Answer 59

no

Question 60

where are alopecia areata lesions distributed?

Answer 60

head/face

Question 61

what aged dogs get dermatomyositis?

Answer 61

young

Question 62

what is dermatomyositis also known as?

Answer 62

ischaemic dermatopathy

Question 63

what breed is predisposed to dermatomyositis?

Answer 63

collies (or similar)

Question 64

is dermatomyositis pruritic?

Answer 64

no

Question 65

what lesions are associated with dermatomyositis?

Answer 65

focal/multifocal alopecia variable hyper/hypopigmentation scaling erosions/crusting

Question 66

what is the distribution of lesions associated with dermatomyositis?

Answer 66

face and extremities