Allergic skin disease Flashcards
List 3 common triggers for allergic skin disease
environmental allergens
Foods
ectoparasites
what hypersensitivity is most commonly involved with allergic skin disease
type 1- immediate - IgE
Define canine atopic dermatitis
A common chronic, relapsing, pruritic and inflammatory skin syndrome with characteristic clinical features- broken down into environmental and food- triggered
List 3 factors needed for environmental canine atopic dermatisis
defective cutaneous barrier function
microbial dysbiosis/ overgrowth/ infection
hypersensitivity reaction
List 2 things targeted in some canine atopic dermatitis treatments
IL31
Janus kinase pathways
what are the pathognomonic signs for canine atopic dermatitis
there are none
If you see crusty ear margins what is it likely to be
sarcoptic mange
Describe the history typically seen with canine atopic dermatitis
nearly always pruritic
scratch, lick, rub, scoot
onset usually 6m-3 yr
may start seasonally –> year round
most will respond to anti-inflammatory dose of corticosteroids
what age does food-triggered atopic dermatitis generally start
can develop at any age
30-50% start at <1yr
More likely than environmental CAD if onset <6mo?
Sensitisation not associated with diet change!
List the clinical signs of food-triggered allergic atopic dermatitis
Skin signs clinically indistinguishable from environmental CAD
+/- Concurrent clinical signs, e.g.
- GI signs
- Urticaria/angioedema
- Malassezia dermatitis
Describe feline atopic syndrome
can manifest in skin, GI tract or resp tract
Describe Feline atopic skin syndrome (FASS)
Inflammatory/pruritic skin syndrome, likely associated with IgE to environmental allergens
Usually young adult – 6mo-5y onset (occasionally older)
Seasonal/ non-seasonal
most commonly presents with one of the 4 reaction patterns
Describe Feline food allergy (FFA)
can occur at any age from 3 months onwards
Non-seasonal
+/- GI/conjunctivitis/respiratory signs
most commonly presents with one of the 4 reaction patterns
How common is contact hypersensitivity
very uncommon
what does contact hypersensitivity need to be differentiated from
contact irritant dermatitis
Describe how contact hypersensitivity present
Sensitisation usually over prolonged period
Lesions in areas of contact only!
Particularly affects sparsely haired regions
Describe how to diagnose contact hypersensitivity
patch test- rarely performed
Describe eosinophilic folliculitis/ furunculosis
Reaction to presumed arthropod bite
Acute onset, highly pruritic
Often affects dorsal muzzle +/- other sites
List the 3 I’s we are trying to control in atopic dermatitis
Inflammation
Itch
Infection
List 4 things we need to balance when treating atopic dermatitis
Product efficacy/ speed of onset`
Risk side effects
Treatment feasibility/ owner compliance
Cost
how does oclacitinib target
JAK inhibitor
what does lokivetmab target
IL-31 monoclonal antibody- only affects pruritus not inflammation
Describe action of glucocorticoids to treat pruritus
highly effective re inflammation and pruritus, rapid onset (24h), inexpensive – but significant risk of side effects, esp with long term use
List 3 things we aim for when using glucocorticoids to treat pruritus
aim to use:
lowest potency product
lowest dose
shortest time
that will be effective
describe the effects of oclacitinib
Excellent antipruritic, some anti-inflammatory effect
NB for treatment of allergic pruritus and dermatitis only,
Descrieb the effects of lokivetmab
Excellent antipruritic but minimal anti-inflammatory effect
Describe the effects of ciclosporin
Excellent anti-inflammatory and antipruritic
takes 1-2 months to work
List 3 ways to improve the skin barrier
topical moisturisers
systemic essential fatty aids
essential oils
List 3 ways to control flare factors
Good ectoparasite control
Avoid overheating
Control microbial populations –e.g. antimicrobial shampoos/wipes/foams
which products are licensed for atopic dermatitis in cats
GCCs and ciclosporin
An 11yo patient that is on oclacitinib for control of canine atopic dermatitis is diagnosed with renal failure. What would be the safest option for ongoing control of his skin condition?
Change to lokivetmab
List 3 common environmental CAD allergens
dust mites
pollens
moulds
What pathway is used to activate and proliferate inflammatory cells
Janus Kinase (JAK) pathways
Describe what happens when there is chronic scratching
activated keratinocytes adn other immune cells
increased monocyte/macrophage recruitment and activation
thickening of the epidermis/stratum corneum
List 3 types of adverse food reactions
food allergy
food intolerance
intoxication
when do the majority of food allergies develop
when the animal is older than 1
what is the most common cause of cutaneous reaction patterns of cats
feline atopic skin syndrome
feline food allergy
feline allergy dermatitis
Describe how to diagnose FASS - feline atopic skin syndrome
eliminate ectoparasites and bacterial/fungal infections
do a diet exclusion trial to rule out FFA
Describe how to diagnose FFA- feline food allergy
diet exclusion trial
are allergy tests of value for diagnosis of canine atopic dermatitis
No
List 4 options for anti-pruritics
glucocorticoids
ciclosporin
oclacitinib
lokivetmab
what is a problem with depo injection of systemic glucocorticoids
diabetogenic and risk HPA axis suppression
how often do we want to give oral glucocorticoids and why
we want the lowest effective alternate day dose, so that we can prevent HPA axis suppression
what are the risks of long term glucocorticoid topical application
systemic absorption and skin thinning
can we put hydrocortisone aceponate spray on broken skin
No
how old do animals need to be in order to have oclacitinib
1 year old minimum
how often do we give lokivetmab
every 4 weeks
how does ciclosporin cause anti-pruritic effects
T-cell suppressor
can antihistamines be used in animals
yes but they are unlicensed
what can allergen-specific immunotherapies be made against
environmental allergens or Malassezia
how long do you have to wait to see if allergen therapy has worked
trial for 12 months
what are the 2 phases of atopy treatment
reactive - initial rapid control
proactive - ongoing maintenance therapy to prevent recurrence
