Allergic Skin Diseases Flashcards
Ctenocephalides felis
most common flea on dogs and cats
describe the flea life cycle
adults on the pet take several blood meals a day, and will lay eggs daily
Eggs fall off and hatch in environment
1st stage 2nd stage 3rd stage larvae
Become the pupa inside a lil silk cocoon and can emerge in 1-2 weeks or in 4 months if delayed
The Pupa
solar opposites is awesome, you should watch it
flea bite INFESTATION vs. HYPERSENSITIVITY
3 Common Causes of Cutaneous Allergic Disease
- Flea bite hypersensitvity
- food induced atopic dermatitis
- environment induced allergic dermatitis
The MAIN symptom of cutaneous allergic disease?
pruritus!
after ruling out ectoparasites of course
regarding flea bite hypersensitvity:
describe lesions and their distribution
primary lesions = papules and crusts
secondary lesions = mostly self-induced from scratching
distribution is primarily the dorsal lumbosacral area (caudal half of pet)
treatment for flea bite hypersensitivity?
get rid of the damn fleas
treat pruritus too (glucocorticoids ideal; apoquel/cytopoint an option)
can you differentiate food allergy patients from environmental allergy patients based on clinical signs alone?
no
food intolerance vs. allergies
are food allergies seen earlier in cats or dogs?
dogs
allergies are most commonly found in younger animals
are food allergies seasonal
no
are environmental allergies seasonal?
yes
but they usually just start that way and can eventually become non-seaso
progress of clinical signs in food allergy dogs
Pruritus, diffuse erythema –> self-trauma from pruritus –> chronic inflammation (lichenification/hyperpigmentation)
clinical signs of food allergy in dogs
Headshakers
Face rubbers
Foot lickers
Belly scratchers
Bottom scooters
THE BIG 5
4 Major patterns of food allergy in cats
- miliary dermatitis
- self-induced symmetrical alopecia
- head and neck pruritus/dermatitis
- eosinophilic granuoma complex
mainly distributed around face, head, and neck
eosinophilic granuloma complex (3)
plaques
granulomas
indolent (rodent) ulcers
additional clinical signs of food allergy in cats
conjunctivitis, hypersalivation, pruritic otitis
are food allergies curable?
no, but it’s controllable
How to diagnose food allergies?
FOOD ELIMINATION AND DIET TRIAL
not those stupid serum IgE tests that clients do at home sometimes
what are hydrolyzed diets
diets where the proteins are broken down to 5kDa or less in size
small enough to sneak past immune system, won’t bind IgE on mast cells
smallest available hydrolyzed protein diet?
ultamino
medium = HP
bigger = z/d
how long does a food trial need to be done?
MINIMUM of 8 weeks
NO other food, treats, supplements, flavored meds, even chew toys!!!!
how do you tell if a food trial worked?
Secondary skin and ear infections should be resolved by the end of the trial
if better, change back to previous diet briefly to see if clinical signs return
Keep in mind can occur at same time as environmental allergy
Define
Canine Atopic Dermatitis
common environmental allergens
- pollen
- house dust mites
- molds
- feathers
- wool
dust mites often nondistinguishable from food allergies b/c non-seasonal
various pathogenesis of environmentally induced allergies in dogs
likely similar in cats but less known/studied
clinical findings of environmental allergies in cats and dogs
Licking/overgrooming, rubbing, rolling, biting, chewing, scratching
ventral distribution, typically earlier in life; progressive disease
regarding environmental allergies
lesions and distribution in dogs
4 major patterns of environmental allergies in cats
- miliary dermatitis
- self-induced symmetrical alopecia
- head and neck pruritus/dermatitis
- eosinophilic granuoma complex
note it’s the same as food allergens!
why is it called eosinophilic granuloma complex?
it stains eosinophiliically, not that it is full of eosinophils
are environmental allergies controllable
yes
but you cannot cure them
multimodal therapy most successful
how to diagnose enviromental allergies
rule out other pruritic disease
seasonal? not food allergies
this IS a CLINICAL diagnosis
Treatment Options for Environmental Allergies
- glucocorticoids
- apoquel
- cytopoint
- cyclosporine (atopica)
- immunotherapy
antihistamines and essential fatty acids minimally effective
remember to also treat your underlying cause and any secondary infections/comorbidities
which is for dogs and which is for cats
prednisone vs. predniSOlone
prednisone = dogs
predniSOlone = cats
can glucocorticoids be used long term?
No
good for short seasonal flare-ups
can you give apoquel to cats?
technically yes but it is off-label use
can you give apoquel to puppies?
NO
clinical trials went real bad for those lil pups
can you give cytopoint to cats? why or why not?
NO
caninized monoclonal antibody against IL-31; starts as a murine and then is wrapped in canine DNA, so the points that bind the IL are just the two on the end
why is cyclosporine not an ideal allergy therapy in dogs?
because it’s expensive as fucking hell
pathogenesis of cyclosporine as an allergen therapy
calcineurin inhibitor, blocking IL-2 and T cell proliferation
same impact as a steroid without giving a steroid
good long term therapy for cats
