Exam 2 - Pruritus Flashcards
what are the big 3 categories of disease that should be considered for a pruritic animal?
parasites, microbial, & allergies
‘what are the infections? why are they there?’
what are examples of each category when approaching a case of a pruritic animal
infections - folliculitis, yeast dermatitis, ectoparasitism
why are they there - allergy (young to middle-aged animals), endocrinopathy (middle aged to senior), cornification (young or specific breeds), anatomical
when confronted with a pruritic patient, what should you rule out first?
parasites & skin infections
what is the pathway of pruritus?
stimulus activates a mediator -> pruriceptor of afferent neuron -> peripheral pathway through the dorsal root ganglion -> central processing & modulation -> interpretation & perception -> response to itch
what are some examples of pruritogenic substances?
histamine, proteases, lipases, eicosanoids, kinins, opioids, substance P, exogenous factors from bacteria/fungi/pathogens
what is epicritic itch? what is the transmission of it through the body?
well-delineated, sharp, spontaneous itch
transmission - myelinated fast-conducting A axons
what is protopathic itch? what is the transmission of it through the body?
poorly-delineated, burning itch
transmission - polymodal nociceptor units with unmyelinated slow-conducting C axons
what is the gate control theory in regards to pruritus?
higher CNS factors may accentuate or lessen the pruritic sensation
anxiety, stress, boredom, playing, & other learned experiences influence the sensation of pruritus
why is mast cell concentration an important factor to consider in a pruritic patient?
mast cells have a higher dermal concentration in the pinnal & ventral interdigital pedal skin compared to other parts of the body - common itchy areas for animals with allergic skin disease
T/F: petting a cat against the direction of hair growth may reveal barbered hair which is highly suggestive of a self-induced injury from pruritus
true
what are some examples of feline cutaneous reaction patterns?
miliary dermatitis, self-induced alopecia, cervicofacial pruritic dermatitis, & eosinophilic granuloma complex
what is a feline cutaneous reaction pattern?
reaction patterns that aren’t diagnoses but rather lesional clues of an underlying pruritic and/or allergic disorder
what is the pruritic threshold?
level of pruritus required to elicit the sensation of pruritus - this level is different for each individual animal
what is the summation effect?
additional stimuli exacerbate & compound the sensation of prurirtus
what immediate side effects are seen with animals on glucocorticoids?
PU/PD/PP & panting
what are some cutaneous side effects associated with animals on glucocorticoids?
alopecia, hair color/texture changes, comedones, scaling, seborrhea, hyperpigmentation, thin atrophic skin, inelastic skin, poor wound healing
what are some musculoskeletal side effects associated with animals on glucocorticoids?
muscle atrophy & weakness (including intercostals & abdominal muscles -> panting & pot belly) & ruptured cruciate ligaments
what is the goal of using glucocorticoids when treating a pruritic animal?
make the animal comfortable with a humane level of itch but not to make them 100% itch-free since the risks of glucocorticoid use begins to trump the benefits of use
T/F: if your patient requires longer than 3-4 months of oral glucocorticoids to manage allergic skin disease, other treatment options should be sought out
true
what drug is FDA labeled for treating canine atopic dermatitis?
atopica - cyclosporine
what drug is FDA labeled for treating feline allergic dermatitis?
atopica for cats - cyclosporine
what drug has an FDA label for canine pruritus associated with allergic skin disease & canine atopic dermatitis?
oclacitnib - apoquel
what is lokivetmab?
cytopoint - caninized (dog-specific antibody) anti-cIL-31 monoclonal antibody (mAb) for canine allergic dermatitis & atopic dermatitis
what is the goal of allergen-specific immunotherapy (ASIT)?
reduce the intensity & severity of clinical signs along with reducing the frequency of/possible need for other therapies best avoided long-term such as glucocorticoids/cyclosporine
how does ASIT work?
ASIT retrains the immune system on how to perceive its environment
what animals is ASIT mainly reserved for?
atopic animals who are affected at least 6 months out of the year who do not tolerate symptomatic therapy or can’t receive symptomatic therapy
for canine atopic dermatitis affecting animals less than 6 months of the year, what are your absolutes you must use for treatments? what are your options?
absolutes - adulticidal flea prevention, infection control, & baths
options - cytopoint, oclacitnib, & glucocorticoids
for canine atopic dermatitis affecting animals more than 6 months of the year, what are your absolutes you must use for treatments? what are your options for animals less than 7-8 years old? what about older than 7-8 years old?
absolutes - adulticidal flea prevention, infection control, & baths
options for 7-8 y/o - cytopoint & ASIT
options for > 7-8 y/o - cytopoint, apoquel, atopica, +/- ASIT