Prurtitis part 1 Flashcards
Pruritis
Sensation of skin that provokes the urge to scratch
True or False: pruritic skin looks the same in most cases
True
General causes of pruritis
Allergens, Ectoparasites, infections
Allergens causing pruritis include
Flea bite allergy
Atopic dermatitis
Cutanous adverse food reaction
Insect bite hypersensitivity/ contact dermatitis
Vaccine/ drugs/ heat and cold/ sunlight/ stress
Ectoparasite causes of pruritis
Sarcoptes
Demodecosis (can have secondary pyoderma)
Cheyletiella
Lice
Chiggers
Infections that can cause pruritis
Pyoderma- bacterial infections
Dermatophytosis
Yeasts
Pruritis in caudal dorsum
Flea allergy
Feet licking, chewing would suggest
Food allergy or atopy
Elbow and ear pruritis
Sarcoptic mange
Seasonal causes of pruritis
Flea allergy
Atopy
Insect allergy
Diseases that are extremely pruritic
Scabies
Flea bite allergy
Food allergy
If the pruritis comes before a lesion, consider these diseases first
Allergies
Scabies
If lesions appear before pruritis, consider these diseases
Demodecosis
Dermatophytosis
How often should pruritis be re-assessed
1-2 weeks after starting treatment
Pathogenesis for flea allergy dermatitis
Type 1 hypersensitivity
most common allergic skin condition
Clinical signs of flea allergic dermatitis
Lumbo-sacral distribution
Pruritic crusting eruption and secondary erythema, seborrhea, alopecia, excoriation, pyoderma, hyperpigmentation and lichenification
Fleas and fle dirt are found
Cats with flea allergic dermatitis can present with
miliary dermatitis
Do fleas or flea dirt have to be present for FAD
No
It can sometimes take only one flea bite to set off the allergic reaction
Why would a dog/ cat not have fleas on them in a case of FAD
Excessive grooming
What ages are most common for FAD
can happen at any age, but 61% of dogs show signs between 1 and 3 years
Describe the Flea antigen test
Intradermal
3 injections- negative control, positive control and flea allergen
Does a negative elevated serum flea allergen specific IgE rule out FAD
No!
Treatment for FAD
Flea eradiacation
Advantage spot on
Imidacloprid and moxidectin
Kills adult fleas before they lay eggs and prevents eggs from being shed
Revolution spot on
Selamectin
kills adult fleas and prevents eggs from hatching
Frontline Plus
fipronil and methoprene
Vectra 3D spot on
Dinotefuran, permethrin and pyriproxyfen an IGR
Prevents development of flea eggs and larva
Promeris spot on
Metaflumizone and amitraz
Kills fleas
Percentage of adults, pupae, larvae and eggs
Adults= 5%
Pupae= 10%
Larvae= 35%
Eggs = 50%
Do more flea eggs live on the pet or in the environment
Environment = 95%
Home cleaning for fleas
Vaccuum with disposal of the bag away from the house
wash animal bedding in hot water weekly and dry for 20 min on high heat
steam clean rugs and carpets
Yard cleaning for fleas
Fleas survive and reproduce in shaded moist areas with plants and organic debris
aka get rid of yard debris
Atopy is
Allergic dermatitis
Atopy can be caused by
hypersensitivity to aeroallergens
type 1 hypersensitivity reaction
Clinical signs of Atopy
Pruritis
Can be chronic or replasing/ seasonal
Usual onset between 4 months to 7 yrs
Paws, face, distal extremeties, elbows, ventrum, otitis externa
Allergy tests (serum or intradermal) detect…
Allergen specific IgE
Raised and disease= allergy
Raised with no disease= subclinical hypersensitivity
What should be avoided before intradermal testing
antihistamines and essential fatty acids for two weeks before
oral or topical steroids for one month
no baths for 5 days
Therapies for Atopy
ASIT ( allergen specific immunotherapy)
Allergen avoidance
Symptomatic relief
ASIT cna be performed in two ways…
Subcutaneous where you increase the dose and concentration slowly
sublingual twice daily
Best meds for atopy symptomatic relief
Glucocorticoids
Cyclosporine A
Oclacitinib
Medium evidence for skin lipid therapy
Distadvantages to corticosteroids
PU/PD/PP and weight gain
Iatrogenic hyperadrenocorticism
Iatrogenic hypoadrenocorticism in withdrawn suddenly
less effective over time
more susceptible ot infections
urinary incontinence
temperment and behavior changes
Cyclosporine A (Atopica)
Very effective for atopy
anti-allergic and immunosuppressive
Oclacitinib (Apoquel)
JAK 1 and JAK 3 inhibitor
Decreases inflammation and itching
Fatty acids canbe used for atopy because
The form arachidonic acid whic can cause less inflammation
Which test is best to identify known environmental allergens causing atopy after performing your inital dermatological examination?
Intradermal allergy test
Most common cause of pruritis in a 4 month old dog
Flea bite dermatitis
Atopic dermatitis is caused by
Type 1 hypersensitivity
Which is the second most common cause of allergic dermatitis in a four month old puppy
Food allergens
Which of the following does not show fair to strong evidence to control pruritis in an atopic dog
Antihistamines
Which product would give local and environmental control in a dog with flea allergic dermatitis
Advantage (imidocloprid)
An owner has decided on intradermal allergy testing and hyposensitization. Qhat percentage of dogs have good to excellent control of atopic dermatitis with hyposensitization?
50%
