Canine Atopic Dermatitis Flashcards
what are the results of uncontrolled atopic dermatitis?
- recurrent multidrug-resistant staph infections and malassezia dermatitis
- recurrent otitis externa
describe practice guidelines for canine AD
- treatment of acute flares of cAD:
-glucocorticoids
-oclacitinib
-cytopoint - treatment of chronic stages of cAD:
-glucocorticoids
-oclacitinib
-cyclosporine
-cytopoint - prevent recurrences of cAD:
-allergen immunotherapy
-food elimination/diet trials
issues with current guidelines (from 2015)
-cAD dogs can at the same time exhibit both acute/subacute flares and chronic skin lesions at different body locations!
-atopic dermatitis is a chronic disease
-cAD dogs have different disease severities so not one drug fits all
describe the different phenotypes of cAD
phenotype 1: severe itch, but mild skin lesions
phenotype 2: generalized skin lesions plus lots of itch
describe the guidelines for cAD treatment
- ID and address flare factors:
- symptomatic treatment of itch and/or inflammation
- prevention of AD flares
compare AIT to symptomatic therapy for cAD
AIT: the only disease modifying therapy!
-ID relevant allergens through intradermal/serologic testing
-then SQ, sublingual, intralymphatic or recomvbinant allergen AIT
symptomatic management: once stop drugs, symptoms return!
-glucocorticoids
-cyclosporine
-oclacitinib
-lokivetmab
-antihistamines
-other
why are drugs shown as equal in clinical efficacy in studies but not in real life?
- drug wash-outs before start of study lead to population bias
-milder AD phenotypes also often included in studies - studies require 50% improvement in itch and clinical scores
- multiple biases in head to head studies between drugs because of different drug dosages/frequencies/duration of therapy
-there is currently no optimal/standard drug dosage or therapy for EVERY case of cAD!
describe general length and use of glucocorticoids
-in most studies, glucocorticoids are tapered after an initial 7 days
-but severely inflamed and itchy skin needs longer duration of oral GCs (2-4 weeks SID then taper)
describe the general effective length and use of cyclosporine
-better changes in pruritis scores when given daily for 6 weeks but
-often tapered to every 2-3 days after 30 days due to expense
describe oclacitinib and lokivetmab efficacy in cAD
- in real life, many dogs are not controlled with these drugs
- many animals not able to achieve reduction in pruritis
-oclacitinib saw rebound after tapering to once daily admin
sum up the current treatment guidelines for cAD
- topical anti-inflammatory/itchy therapy remains the mainstay for human and canine AD
- current canine AD guidelines do NOT provide a defined first line agent algorithm for practitioners or which systemic agent to select
- current symptomatic drugs are considered equal in efficacy for therapy but real life practice shows differences between agents
- further characterization of clinical phenotypes in cAD and clinical responses to different symptomatic drugs is needed
describe reactive versus proactive
reactive therapy: get control/induction of remission
-anti-inflammatory therapy (2x daily) until no visible skin lesions
- proactive therapy: keep control/maintenance of remission
-low dose, continuous intermittent application of anti-inflammatory therapy to previously affected AD skin
-mainstay of treatment of every human patient - why?
-nonlesional AD skin: macroscopically no AD skin lesions visible BUT is always molecularly active and will cause a disease flare (microscopic inflammation) due to tissue resident memory T cells - which agents used?
-humans: tacrolimus
-canine: triamcinolone spray, hydrocortisone spray, mometasone furoate cream/ointment (topical glucocorticoids)
-topical glucocorticoids alone reduce itch and clinical lesions!!
-topical glucocorticoids also improve efficacy of systemic agents like JAK inhibitors, lokivetmab - how use:
-majority of patients with topical intermittent (tuesday/saturday per week) proactive glucocorticoid therapy to previously affected AD skin remained controlled at 12-14 weeks
sum up reactive/proactive therapy for AD
- topical anti-inflammatory/itch therapy remains mainstay
- proactive topical glucocorticoid therapy can extend AD remission for several month
- topical glucocorticoids improve efficacy of oclacitinib
- main limitation of proactive steroid topical therapy is lack of long-term safety
describe the concept of reactive/proactive systemic therapy in cAD
the breadth of target immune inhibition determines the timing of their use!
broadest to narrowest:
-glucocorticoids: rapid improvement and broad targeting for reversal of cAD inflammation in short-term use!/reactive treatment
-cyclosporine
-ilunocitinib
-oclacitinib
-lokivetmab (cytopoint): more proactive treatment to keep control
how would you handle a refractory cAD case?/how to select a drug?
ex.) 5 months of daily lokivetmab + oclacitinib + topical antiseptic shampoo/spray/oral cephalexin
how to choose a drug:
-phase 1: reactive therapy; choose drugs for itch/inflammation + secondary complications (broader range: glucocorticoids, cyclosporine, ilunocitinib) until subclinical remission
-phase 2: proactive topical therapy twice weekly with topical glucocorticoids + re-usage of agent like injectable lokivetmab
-if super refractory, start cyclosporine in phase 1 and continue as needed through phase 2 or switch to injectable lokivetmab JAK inhibitors (systemic control through phase 2 is difference)
