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