derm

Question 1

what are the four allergic patterns in cats?

Answer 1

1. milliary dermatitis
2. head/neck pruritis
3. self-induced hypotrichosis/alopecia
4. eosinophilic granuloma complex

Question 2

DDX for miliary dermatitis

Answer 2

flea allergy dermatitis
food allergies
dermatophytosis
pemphigus
lymphoma
parasites
bacterial folliculitis

Question 3

DDX for HNP

Answer 3

flea allergy dermatitis
food allergies
dermatophytosis
pemphigus
feline herpes dermatitis
mosquito bite derm
demodicosis
ear mites

Question 4

SIAH DDX

Answer 4

endocrinopathy
bladder disease

Question 5

eosinophilic granuloma complex lesions, causes

Answer 5

causes: FASS, ectoparasites, infection, idiopathic

eosinophilic plaque-> inner thigh, abdomen

eosinophilic granuloma-> caudal thigh, face, oral cavity

indolent ulcers-> associated w licking, lips

Question 6

eosinophilic granuloma complex tx

Answer 6

plaque-> steroids, atopica, abx
granuloma-> steroids, atopica, immunotherapy
indolent ulcer-> abx

Question 7

papule ddx

Answer 7

bacterial folliculitis

Question 8

pustule ddx

Answer 8

pyoderma, pemphigus, demodicosis

Question 9

crust ddx

Answer 9

secondary lesion- bacterial folliculitis, pemphigus

Question 10

comedones ddx

Answer 10

dermatophytosis, demodicosis

Question 11

epidermal collarette ddx

Answer 11

bacterial folliculitis, pyoderma

Question 12

nasal planum disease ddx

Answer 12

discoid lupus erythematosus, mucocutaneous pyoderma,

Question 13

canine atopic dermatitis distribution, pathogenesis

Answer 13

immune dysfunction: th2 cells, IL31, IL17, IL33

leads to impaired skin barrier function->increased allergen penetration

Question 14

CAD allergens

Answer 14

dust mite, dust, molds, grass, weeds, dander

Question 15

CAD C/S

Answer 15

pruritis
primary lesions-> erythema and papules
secondary lesions mostly-> excoriation, infection
ears, face, inguinal area, paws

Question 16

CAD dx

Answer 16

1. r/o other diseases that look similar-> ectoparasites, food trial, infection
2. detailed analysis of hx, C/S (favrot’s criteria)
3. demonstrate IgG-> intradermal testing, serum IgE

no pathognomonic test

Question 17

CAD tx

Answer 17

Question 18

apoquel MOA

Answer 18

janus kinase inhibtor-> inhibit cytokines involved in itching/CAD
fast-acting-> use for acute flares

Question 19

cytopoint MOA

Answer 19

canine monoclonal Ab-> inactivates IL31

SQ injection, lasts 4-8wks
fast acting-> acute flares

Question 20

atopica MOA

Answer 20

calcineurin inhibitor
slow acting (4-8wks)
has adverse effects-> gingival hyperplasia

Question 21

steroids MOA

Answer 21

most effective for itching, allergic inflammation
pred
medrol-> dexamethasone most potent
used for acute rxns, ear stenosis, pododermatitis

topicals: soft steroids (hydrocortisone aceponate, mometasone), tacrolimus (cyclosporine)

Question 22

ASIT

Answer 22

only tx that can stop progression: promotes th1 response, regulatory cytokines
SLIT or SCIT-> use intradermal testing to find allergens, take 12-18m for benefit

Question 23

CAD flare causes, tx

Answer 23

food allergens, ectoparasites, seasonal exposure, INFECTION

tx- steroids, apoquel, cytopoint

Question 24

Answer 24

malassezia- yeast infection

Question 25

Answer 25

demodex

Question 26

Answer 26

scabies (ear edges)

Question 27

Answer 27

lice

Question 28

Answer 28

flea allergy dermatitis

Question 29

pemphigus foliaceus sites, lesions

Answer 29

attacks outer layer of keratinocytes papules/pustules-> crusts affects face, nasal planum, pinnae, paws, nailbed in cats

Question 30

pemphigus DDX, dx

Answer 30

DDX: dermatophytosis, pyoderma, demodex dx-> skin scrape (r/o demodex) cytology- acantholytic cells, neutrophils biopsy is definitive

Question 31

pemphigus tx

Answer 31

combination pred and atopica (immunosuppressive) in dogs, pred alone in cats

Question 32

immunosuppressive tx goals

Answer 32

combination therapy-> minimize side effects avoid triggers, remission is often impossible find lowest dose and frequency to control signs-> minimize side effects

Question 33

DLE signs, lesions, DDX, dx, tx

Answer 33

lupus confined to skin(face) C/S- depigmentation of nose, erosion/ulceration dx- cytology, scrape, DTM to r/o other dermatoses biopsy trial abx DDX: pemphigus, dermatophytosis, mucocutaneous pyoderma tx- tetracycline, niacinamide, steroids if necessary avoid sun, sunscreen

Question 34

otitis externa factors

Answer 34

most common cause is CAD

Question 35

ototoxic drugs? which ones are the worst?

Answer 35

aminoglycosides, ceruminolytics chlorhexidine

Question 36

otitis workup

Answer 36

mild, first time cases: antiseptic, steroids, topical abx recurrent: workup underlying cause - allergy testing, food trial - r/o parasitic recurrent w severe debris: deep ear flush, CT

Question 37

otitis media C/S, dx

Answer 37

extension from ear canal, resp disease, primary in bullae (neoplasia, polyp) C/S- head tilt, horners, pain opening mouth, ruptured tympanic membrane dx- otoscopy, CT tx- myringotomy, flush debris from middle ear, 6-8wks abx

Question 38

otitis interna C/S, dx, tx

Answer 38

extension of otitis media-> vestibular signs (peripheral) tx- same as otitis media

Question 39

pyoderma organisms

Answer 39

staph pseudointermedius, schleiferi, aureus

Question 40

superficial pyoderma

Answer 40

pustules->bacterial folliculitis (below)

Question 41

deep pyoderma

Answer 41

furnuculosis->abscess-> cellulitis

Question 42

pyoderma dx, causes

Answer 42

causes: allergies, endocrinopathies, systemic disease, immune conditions cytology: cocci

Question 43

pyoderma tx, when to recommend culture

Answer 43

try topicals first if using oral-> min 3 wks culture if not responding, MRSP, hx of abx, deep infection first line abx-> clindamycin, cephalexin

Question 44

diagnostic technique/workup

Answer 44

cytology: impression, swab skin scrape otic swab, mineral oil prep skin scrape: superficial or deep woods lamp for dermatophytosis dermatophyte culture trichogram culture biopsy

Question 45

skin scrapes

Answer 45

for dermatitis superficial- scabies deep for demodex use spatula around the face

Question 46

when to use trichogram

Answer 46

pruritis in cats alopecia demodex dermatophytes endocrine colour dilution

Question 47

dermatophyte culture

Answer 47

m canis- white fluffy gypseum- flat, cream T. mentagrophytes- white powdery contaminants are darker

Question 48

when to culture

Answer 48

lack of response to abx pyoderma w resistance deep infection suspect anaerobe non reponsive otitis atypical bacteria

Question 49

when to biopsy

Answer 49

immune-mediated disease severe skin disease systemic disease, suspect neoplasia unecognized lesions deep lesions lack of response to tx

Question 50

how to sample for biopsy?

Answer 50

multiple samples, different lesions alopecia-> center hypopigmentation-> early lesions

Question 51

which dermatoses are zoonotic?

Answer 51

scabies (mild) dermatophytosis: m. canis, gypseum, t. mentagrophytes