Final studying Flashcards
what are the 4 reaction patterns in feline atopic skin syndrome?
- miliary dermatitis (MD)
- self-inflicted alopecia/hypotrichosis (SIAH)
- head and neck pruritis (HNP)
- eosinophilic granuloma complex
describe miliary dermatitis in cats
small, crusted, erythematous papules
often assoc with pruritis and secondary cutaneous lesions
may occur anywhere but are common on trunk and neck
describe self-inflicted alopecia/hypotrichosis in cats
secondary to fur pulling/biting/chewing/licking
caudoventral truncal regions, flank, lumbar region, limbs
underlying skin often normal and pruritis assoc with this alopecia is often mistaken by owners as normal grooming
cants often demonstrate pruritic behaviours when alone so owners mistake this for hair falling out
describe head and neck pruritis in cats
excoriations, erosions, alopecia, erythema (can be quite dramatic)
self-trauma to face and pinnae
describe eosinophilic granuloma complex in cats
eosinophilic granulomas, eosinophilic plaques (pictured), indolent ulcers
EG: nodules, plaques, masses that can affect the head, oral cavity, chin, and paw/paw pad. erosion/ulceration may be present, pruritis is variable
- linear granuloma on rear limbs
EP: erythematous, usually pruritic, often eroded plaques and masses usually on caudoventral abdomen and medial thighs (but can appear anywhere)
IU: upper lips, near midline, often thickened and fibrotic
What is this?
head and neck pruritis (HNP) in a cat with feline atopic skin syndrome (FASS)
What is this?
head and neck pruritis (HNP) in a cat with feline atopic skin syndrome (FASS)
What is this?
self-inflicted alopecia/hypotrichosis (SIAH) in a cat with feline atopic skin syndrome (FASS)
What is this?
self-inflicted alopecia/hypotrichosis (SIAH) in a cat with feline atopic skin syndrome (FASS)
What is this?
miliary dermatitis (MD) in a cat with feline atopic skin syndrome (FASS)
What is this?
miliary dermatitis (MD) in a cat with feline atopic skin syndrome (FASS)
What is this?
eosinophilic granuloma complex – eosinophilic granuloma (linear)
What is this?
eosinophilic granuloma complex – eosinophilic plaques
What is this?
eosinophilic granuloma complex – indolent ulcers
What is this?
eosinophilic granuloma complex – eosinophilic granulomas (roof of mouth) with an indolent ulcer (upper lip)
You have a cat showing some of the feline hypersensitivity reactions. List reasons why these could be present. (list ddx)
- feline atopic skin syndrome*
- food allergy*
- flea allergy*
- dermatophytosis
- other parasitic dermatoses (Demodex gatoi, pediculosis, Cheyletiellosis, Notoedres cati)
- infection
- psychogenic
- consider immune-mediated (pemphigus foliaceus), endocrine, or neoplastic if systemically ill or C/S elicit suspicion
Which feline hypersensitivity reactions respond to antibiotics?
indolent ulcers and eosinophilic plaques
not eosinophilic granulomas!
You have a pruritic cat presenting with signs of feline hypersensitivity reactions. Describe a general approach to this case, and cases like it.
- Isoxazoline (ectoparasite control) (all in contact animals)
- strict diet trial
- tx secondary infections
- perform dermatophyte testing
- consider UTI in cats with SIAH affecting skin overlying bladder
- consider phychogenic behaviour when SIAH or HNP is present, esp if other abnormal behaviours exist.
- Oclacitinib/apoquel or glucocorticoids (prurits)
- recheck in 8 weeks and if signs persist, then likely FASS
What is the distribution of lesions of atopic dermatitis?
periocular, muzzle, paws, ventral metacarpal and metatarsal regions, perianal, inguinal, axillary, cubital fold
List primary causes of otitis externa
- hypersensitivity disorders (atopic dermatitis, food-induced atopic dermatitis) [most common]
- endocrine (esp hypothyroid)
- parasites (Otodectes, Demodex, Sarcoptes)
- immune-mediated diseases (pemphigus)
- masses
- foreign bodies
- glandular disorders (ex. sebaceous adenines, seborrheic disorders)
incite inflammation directly
List secondary causes of otitis externa
- Malassezia
- bacterial (staph, pseudomonas)
List predisposing factors of otitis externa
- large and pendulous pinnae (cocker spaniel, springer spaniel
- narrow ear canal (shar pei)
- excessive hair in ear canal (poodle)
- excessive moisture (swimming, bathing)
- obstructive lesions (neoplasia, polyps)
- systemic disease (immunosuppression, ex hypothyroid)
may not directly cause otitis externa, but increase the risk of development
List perpetuating factors of otitis externa
- bacteria
- yeast (Malassezia)
- otitis media
- glandular hyperplasia
- stenosis
- thickening and edema
- calcification
- tympanic membrane changes
- hyperkeratosis with debris exfoliated into canal
- fold development in ear canal
- biofilms
- interruption in epithelial migration
not responsible for initiation of otitis, but do cause the disease to continue once established
Which drugs cause ototoxicity?
- aminoglycosides
- chlorhexidine (high concentration chlorhex is MOST CONCERN)
- cerumenolytics (although squalene is not ototoxic and most effective)
- many carrier agents
- long acting agents
- more concern in cats
What are the signs of otitis media?
- otitis externa (most commonly!)
- increased pain, increased head shaking
- lethargy, inappetence
- pain opening mouth
- facial nerve paresis/paralysis
- Horner’s syndrome
- parasympathetic damage –> nasal planum is dry and crusty + hyperkeratotic (xeromycteria), KCS
- tympanic membrane abnormalities
what are the signs of otitis interna?
- peripheral vestibular signs (head tilt, horizontal/rotary nystagmus, circling, falling toward side of lesion)
- otogenic meningitis
- facial nerve paralysis
- usually an extension of otitis media
what is the difference between a primary and secondary lesion?
primary: direct manifestation of a disease process
secondary: lesions that evolve from a primary lesion
some lesions can be both primary and secondary
what is a macule? is it primary or secondary?
flat area of colour change <1cm diameter
primary
what is a papule? is it primary or secondary?
circumscribed elevated lesion <1cm diameter
primary
what is a patch? is it primary or secondary?
flat area of colour change >1cm diameter
primary
what is a pustule? is it primary or secondary?
circumscribed elevated lesion filled with pus
primary
what is a plaque? is it primary or secondary?
flat-topped, raised skin lesion >1cm diameter
idk it actually doesn’t say in the notes
what is a vesicle? is it primary or secondary?
thin-walled fluid filled lesion <1cm diameter
primary
what is a bulla? is it primary or secondary?
thin walled fluid filled lesion >1cm diameter
primary
what is a nodule? is it primary or secondary?
solid mass >1cm diameter
primary
what is a wheal? is it primary or secondary?
flat, firm, raised, emematous lesion; larger and coalescing wheals create angioedema (basically, they’re hives)
primary
what is a cyst? is it primary or secondary?
epithelial lined cavity containing fluid, cellular, follicular, or sebaceous debris
primary
what is alopecia? is it primary or secondary?
aka hypotrichosis
decreased amount of hair/fur
can be both primary or secondary
what is a scale? is it primary or secondary?
fragments of surface epithelium
can be both primary or secondary
what is a crust? is it primary or secondary?
accumulation of cellular debris (pus, blood, keratinocytes)
can be primary or secondary
what is a follicular cast? is it primary or secondary?
keratinous debris adhered to proximal hair shaft
can be primary or secondary
what is a comedone? is it primary or secondary?
dilated and plugged hair follicles
can be primary or secondary
what is hypopigmentation? is it primary or secondary?
decreased epidermal melanin
can be primary or secondary
what is hyperpigmentation? is it primary or secondary?
increased epidermal melanin
can be primary or secondary
what is leukoderma? is it primary or secondary?
white skin
can be primary or secondary
what is leukotrichia? is it primary or secondary?
white fur
can be primary or secondary
what is melanoderma? is it primary or secondary?
dark skin
can be primary or secondary
what is melanotrichia? is it primary or secondary?
dark fur
can be primary or secondary
what is an epidermal collarette? is it primary or secondary?
circular alopecic lesion with peripheral scale and develops from ruptured pustule or bulla
secondary
what is a scar? is it primary or secondary?
fibrous tissue that has taken the place of dermis and subcutis
secondary
what is excoriation? is it primary or secondary?
erosion or ulcerations from self-trauma
secondary
what is erosion? is it primary or secondary?
partial thickness epidermal defect (not to level of dermis)
secondary
what is an ulcer? is it primary or secondary?
full thickness epidermal defect (to level of dermis)
secondary
what is lichenification? is it primary or secondary?
thickened, elephant-like skin, usually also hyper pigmented
secondary
what is a callus? is it primary or secondary?
hyperplastic, thickened, alopecic lesions typically on pressure points
secondary
list the ddx: erythema
allergic inflammation, malassezia, bacterial overgrowth
anything that can cause inflammation can cause erythema
list the ddx: hypopigmentation
lupus (nasal planum), cutaneous lymphoma (periocular and perioral), senile (top ones)
list the ddx: hyperpigmentation
healed bacterial pyoderma (post-inflammatory), melanoma, viral plaques, endocrine dz, senile
list the ddx: leukotrichia
vitiligo, alopecia arrieta (immune system attacks hair follicle or shaft and grows back white)
list the ddx: papule
allergic dermatitis, bacterial folliculitis, demodicosis, dermatophytosis, parasitic, actinic disease, drug reaction, pemphigus early in disease
list the ddx: pustule
bacterial pyoderma, ectoparasites, pemphigus foliaceus, pustular dermatophytosis, drug reaction
list the ddx: plaque
infection dermatoses (pyoderma, dermatophytosis), eosinophilic plaques, viral plaques, neoplasia, sterile panniculitis, sterile granuloma/pyogranuloma syndrome
list the ddx: macule
erythema multiforme
list the ddx: vesicle/bullae
bullus pemphigoid, systemic lupus, vesicular cutaneous lupus, drug reaction, contact dermatitis, mucous membrane pemphigoid, mucinosis
list the ddx: cyst
hair follicle cyst
list the ddx: wheal
acute allergic reaction
list the ddx: crusts
pyoderma, pruritis (any pruritic disease), demodicosis, scabies, pemphigus foliaceus, seborrhoea
list the ddx: scale
anything causing skin inflammation (seborrhoea, ichthyosis, scabies, cutaneous lymphoma)
if crust in elbow = scabies
list the ddx: comedones
chin acne, demodicosis, ringworm, endocrine dz, Sphinx cats, hairless dogs
list the ddx: lichenification
atopic dermatitis, self trauma
list the ddx: follicular casting
sebaceous adenitis, Vit A responsive dermatitis, seborrhoea, demodicosis, dermatophytosis
list the ddx: excoriation
self-induced lesions secondary to pruritis: consider all pruritic conditions
which diseases are zoonotic?
- scabies (mild)
- dermatophytosis (M. canis; M. gypseum and T. mentagrophytes less so)
- Cheyletiellosis
- staph aureus
what is the pattern distribution of scabies?
ear margins, elbow, hock, periocular region, inguinal/ventral
becomes generalized if untreated
what is the pattern distribution of flea allergy?
caudal dorsum/tail base, neck, inguinal
what is the pattern distribution of demodex?
paws, head/face, but can be haphazard
what is the pattern distribution of pediculosis and Cheyletiella?
dorsum
what is the pattern distribution of yeast dermatitis?
paws, face, inguinal, axillary, ventral neck
what are the diseases that have a pattern distribution that mimic allergies in dogs?
scabies, fleas, demodex, yeast, lice/cheyletiellosis, CAD/food allergy
Why do we perform allergy testing in animals?
ID environmental allergens for immunotherapy or avoidance
NOT FOR DIAGNOSIS
what is the distribution of lesions for pemphigus foliaceus?
- face
- nasal bridge and planum (symmetrical crusting)
- pinnae
- paw pads (crust, pustular discharge) (dog)
- nailbed (cat)
- nipple (cat)
what are the differences b/t how dogs and cats present with pemphigus foliaceus?
dog:
- paw pads have crusting and fissures that appear like hyperkeratosis
cats:
- nail folds and nipples affected
- severe caseous, purulent, or crusty exudate from nail folds specifically
what are our goals for treating auto-immune diseases?
minimize side effects of treatment and give them the highest quality of life possible
not to give them normal skin!
what are the C/S of pemphigus foliaceus?
papules, pustules, crusts, epidermal collarettes with erosion and secondary alopecia
crusts usually yellow to tan
(site predilection in another flashcard)
lethargy, inappetent, febrile in mod-severe cases
Who is he? what caused him?
acantholytic keratinocytes (and neutrophils)
caused by pemphigus complex (PF most commonly)
what are the main ddx for pemphigus foliaceus?
dermatophytosis, pyoderma, demodex
how do you diagnose pemphigus foliaceus?
- cytology –> acantholytic keratinocytes!!
- skin scrape to rule out demodex
- biopsy for definitive diagnosis
how do you treat pemphigus foliaceous?
pred ± atopica
what is the site predilection for discoid lupus erythematosus?
confined to skin, usually just the face
may also involve ears, perianal areas, occasional non-facial regions
what are the C/S of discoid lupus erythematosus?
- depigmentation of nasal planum
- loss of cobblestone appearance
- erosion/ulceration
- scaling/crusting
- (site predilections in another flashcard)
how do you treat discoid lupus erythematosus?
Vit E, essential fatty acids, topical tacrolimus if just confined to nasal planum, steroids if necessary, avoid sun at peak hours or put on sunscreen
Which diseases affect the nasal planum?
- discoid lupus erythematosus (most common)
- pemphigus foliaceus
- pemphigus erythematosus
- mucocutaneous pyoderma
- uveodermatologic syndrome
- vitiligo
- cutaneous lymphoma
- squamous cell carcinoma (cats esp)
- idiopathic nasodigital hyperkeratosis
- parasympathetic nose
When should you perform a biopsy?
- suspect immune-mediated or auto-immune disorder
- severe skin disease
- suspect systemic disease
- suspect neoplasia
- unusual or unrecognized lesions
- nodular or deep skin lesions
- lack of response to therapy
What lesions do you want to biopsy?
Primary lesions!!!!»_space;» secondary
- avoid scarring and ulcers
- alopecia: centre
- hypopigmentation: early lesion
- multiple samples, variety of lesions
what are the lesions of superficial pyoderma?
pustules, papules, crusts, epidermal collarettes
what are the lesions of deep pyoderma?
follicle ruptures –> furunculosis
nodules, draining tracts, erosions, ulcers
what are the lesions of CAD?
primary: erythema, papules
secondary: excoriation, alopecia, lichenification, moist dermatitis, infection
how do you diagnose CAD?
no clinical test
- rule out other diseases
- skin scrapes
- cytology
- food trial
- tx/rule out ectoparasites
- ID and tx infections - detailed analysis of hx and C/S –> Favrot’s criteria (need 5/8)
- age of onset <3 yrs
- mostly indoor
- corticosteroid responsive pruritis
- chronic or recurrent yeast infections
- affected front feet
- affected ear pinna
- non-affected ear margins (if yes, then scabies!)
- non-affected dorso-lumbar area (if yes, then fleas!) - demonstration of IgE and ID allergens (intradermal skin test, serum IgE)
why do flare ups occur in allergy pets?
- infection (most common!) [Staph, yeast]
- seasonal or increased exposure to allergen
- food allergy/other allergy development
- fleas or other ectoparasites
- change in meds
how do you treat a flare up in an allergy pet?
fast acting relief –> oclacitinib, lokivetmab, corticosteroids
NOT CYCLOSPORINE
what is the generic name for apoquel?
oclacitinib
what is the generic name for cytopoint?
Lokivetmab
what is the MOA for apoquel? any considerations with it?
JAK1 inhibitor –> binds to cytokine receptors and inhibits activity of many cytokines involved in CAD
fast-acting (useful for acute flares)
label age >12 mo
what is the MOA for cytopoint? any considerations with it?
caninized monoclonal antibody –> targets, binds, inactivates IL-31
fast-acting (useful for acute flares)
DOES NOT WORK ON CATS
lasts 4-8 weeks
what is the MOA of cyclosporine? any considerations with it?
calcineurin inhibitor –> calcineurin activates IL-2, and IL-2 activates lymphocytes, so cyclosporine stops that whole train
slow acting (not good for flares!)
adverse effects: GI signs, gingival hyperplasia, hypertrichosis, immune-suppression (secondary infection)
label age >6mo
more anti-inflammatory than the others – not really used as first line tx
why can’t you use cytopoint on a cat?
it’s a CANINIZED antibody! made just for doggies
if given to a cat, it will induce an antibody response and make things worse
why do we do bacterial cultures in pyoderma cases?
ID causative organism from lesions and to select appropriate abx
NOT TO DIAGNOSE!
when should you perform a bacterial culture?
pyoderma dx (already made the dx)
- rods seen on cytology (atypical bacteria)
- deep/severe pyoderma present
- infection doesn’t respond to first-line therapy or relapses frequently
- patients with a hx of resistant infection or recent use of Abx
- suspect anaerobic culture
- ear culture: non-responsive otitis externa or media/interna
how do you treat pyoderma?
topical therapy always!!!
- chlorhexidine shampoos/wipes/sprays
- topical Abx
systemic therapy
- cephalexin, clindamycin, cefpodoxime –> first-line empirical treatments (for treatment-naive S. pseudintermedius)
- do C&S if indicated
topical for superficial, systemic + topical for deep
always assess for underlying causes, like CAD
What organism is this?
Microsporum canis (dermatophyte)
fluffy, white, raised, cottony
What organism is this?
Microsporum gypseum (dermatophyte)
flat, cream to tan, granular
What organism is this?
Trichophyton mentagrophytes (dermatophyte)
white to cream, powdery or cottony
What organism is this?
Microsporum canis (dermatophyte) macroconidia
abundant, pindle shaped, knobbed, thick cells, more than 6 cells ± microconidia
What organism is this?
Microsporum gypseum (dermatophyte) macroconidia
spindle, thin walls, rounded ends, less than 6 cells ± microconidia
What organism is this?
Trichophyton mentagrophytes (dermatophyte)
hardest to find, cigar shaped, thin walled, narrow attachment to hyphae, spiral hyphae, globose clusters of microconidia
What organism is this?
yeast
What organism is this?
not well stained yeast lmao
What organism is this?
cocci
if on skin, most often will be Staph pseudintermedius
What organism is this?
rods
if rods, then culture
What organism is this?
dermatophytosis
What organism is this?
environmental mold spores
what is this?
eosinophilic plaque
eosinophils have arrows, macrophages have arroewheads
what is this?
mast cells
intense granulation!
what is this?
soft tissue sarcoma
what is this?
pemphigus foliaceus
“fried egg cells” = pathognomonic (aka acantholytic keratinocytes)
what is this?
cutaneous lymphoma
what is this?
sebocytes
What organism is this?
Demodex canis (mite)
only in dogs!
What organism is this?
Demodex injai
only in dogs!
What organism is this?
Demodex gatoi
only in cats!
What species is this? What disease does it cause?
Sarcoptes scabei var canis
causes scabies / sarcoptic mange
what are these?
Sarcoptes scabei var canis eggs
you get this organism from a skin scraping from a dog. what is it?
Demodex canis
how do you treat ectoparasites generally?
isoxazolines (afoxolaner/NexGard, sarolaner/Simparica/Revolution Plus, fluralaner/Bravecto)
Who is this man?
Otodectes cynotis (ear mite)
Who is this man?
Cheyletiella (there are 3 species, but I don’t wanna remember them lmao)
who is this man?
Notoedres cati
they have a dorsal anus, compared to Sarcoptes mites having a terminal anus
What is this cytology slide of?
pyoderma case
can see inflammatory cells and bacteria
what species of lil guy fluoresces under a Wood’s Lamp?
Microsporum canis (ringworm)
dermatophytosis (only the 1 species above)
Who are they?
Malassezia
Who are they?
Malassezia
What is this?
fungal elements from a slide impression in a dog with dermatophytosis
What is a soft steroid? What are their names?
topical steroid that is very potent in the skin but metabolized to a very weak steroid once it gets into circulation
- Mometasone
- Hydrocortizone aceponate
What is the generic name for Atopica?
Cyclosporine
