SASH : Atopic dermatitis treatment by Dr Linda Vogelnest

Veterinary consultancy content from SASH

1. Atopic Dermatitis
Linda Vogelnest BVSc MACVSc FACVSc

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Atopic Dermatitis
“Changing” disease…. New Definition:
International Task Force (2002) canine atopic
dermatitis
-“Genetically-predisposed
-Inflammatory & pruritic allergic skin
disease
-Characteristic clinical features
-Associated most commonly with IgE
antibodies to environmental allergens”
OLIVRY, DE BOER, GRIFFIN, HALLIWELL et al (2001). Veterinary
Immunology and Immunopathology 81: 143-146
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Atopic Dermatitis
Genetic Influence:
1.Immunological dysfunction
–T-lymphocyte driven
–Mast cells, IgE
•2 subsets:
–High allergen-specific IgE producers
–Low allergen-specific IgE producers
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Atopic Dermatitis
Genetic Influence:
1.Immunological dysfunction
–T-lymphocyte driven
1.Skin barrier dysfunction
–Lipid changes:
•more heterogeneous, thinner, shorter
lamellae
•↓ ceramides (non lesional & lesional
skin)
–Protein changes:
↓ filaggrin expression (beagles)
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Microbes,
allergens
Water

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Atopic Dermatitis
Genetic Influence
1.Immunological dysfunction
–T-lymphocyte driven
1.Skin barrier dysfunction
–Lipid changes
–Protein changes
Environmental Influence
–Allergen exposure
–Microbe exposure (“hygiene
hypothesis”)
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Microbes, allergens
Water

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Atopic Dermatitis
•Atopy = broad allergic group
•Humans
–allergic rhinitis
–allergic asthma
–atopic dermatitis (eczema, AD)
•Dogs/Cats – AD most common
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AD: Treatment
Multi-faceted approach
1.Acute flare plan
2.Long-term management plan
Options:
1.Minimise allergen &/or irritant exposure
2.Immunotherapy
3.Symptomatic therapy
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OLIVRY, DE BOER (2010). Treatment of canine atopic dermatitis: 2010 clinical practice guidelines from the International Task Force on Canine Atopic
Dermatitis. Veterinary Dermatology 21: 3; 233-248.

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AD: Treatment
1.Minimise allergen exposure
–requires skin test (or allergen-specific IgE serum test) →
id allergens
–most useful dust mites, mould spores
•see human literature
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AD: Treatment
1.Minimise irritant exposure
–variety of factors
•grass
•certain fabrics: wool
•heat
•dryness
•shampoos (rarely)
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AD: Treatment
1.Minimise allergen/irritant exposure
2.Immunotherapy
–requires skin test (or allergen-specific IgE serum test) → id
allergens
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AD: Immunotherapy
(allergen-specific)
•Potentially changes allergic response
–T-helper subset change (II to I)
–60-70% improve (20-30% excellent)
•Recommended when
–allergy severe
–allergen avoidance not possible/not effective
–symptomatic tx ineffective or → side effects
–preferred to avoid medications
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AD: Immunotherapy
(allergen-specific)
•Requires owner commitment
–Ideally minimum 2-yr program
–6-12 months to see benefit in many
–Average cost $10-15/wk (~$300 per 7mnths supply)
•Side effects - very rare
–­ itch (→ change dose)
–Urticaria; Anaphylaxis - extremely rare
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AD: Treatment
1.Minimise allergen exposure
2.Immunotherapy
3.Symptomatic tx
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23. www.sashvets.com
AD: Treatment
1.Minimise allergen exposure
2.Immunotherapy
3.Symptomatic treatment
1.Acute flare plan
2.Long-term management plan
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OLIVRY, FOSTER et al (2010). Interventions for atopic dermatitis in dogs: a systematic review of randomized controlled trials.
Veterinary Dermatology 21: 1; 4-22.

24. www.sashvets.com
AD: Treatment
1.Minimise allergen exposure
2.Immunotherapy
3.Symptomatic treatment
1.Acute flare plan
•Treat active infections – when present!
•Soothing
•Anti-inflammatory
•Limit self-trauma
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AD: Treatment
1.Minimise allergen exposure
2.Immunotherapy
3.Symptomatic treatment
1.Acute flare plan
2.Long-term management plan
1.Infection prevention – when relevant!
2.Anti-inflammatory
3.Skin barrier repair
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AD: Symptomatic Tx
A.Safest Options
•Antihistamines
•Fatty acids
•Shampoos
•Moisturisers/topical soothing products
•Limit self-trauma
NB Rarely spectacular response with severe acute flares;
most effective as part of long-term plan
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AD: Symptomatic Tx
Antihistamines
–Block histamine effects (not IgE, Langerhan’s cells, T cells, cytokines
etc etc)
–Safe
–Variably effective (rarely spectacular)
–Trial a number
–Little pharmacokinetics (dogs or cats): dose rates?
–Higher success cats, help some dogs
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AD: Symptomatic Tx
Fatty acids
–¯ pruritus? - altered eicosanoid
production
–improve barrier function (stratum
corneum)
•Omega-3
–fish oil (pump bottle, capsules); flax seed oil
•Omega-6
–Evening primrose oil (50-100mg/kg sid)
–Cold-pressed sunflower/safflower oils (2mls/kg
sid)
–borage oil, blackcurrant oil
•Combinations e.g. Megaderm®
–­ energy intake (¯ other dietary intake)
–care with pancreatitis?
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AD: Symptomatic Tx
Shampoo Therapy
–Regular appropriate shampoo therapy
helps vast majority atopic dogs (& can
help cats)
•wkly → twice wkly
•skin drying rarely problem
•NOT too vigorous rubbing of coat against
lay of hair
•10-minute contact time for medicated
shampoo (use timer)
•rinse well
–Avoid drying shampoos in most cases:
tar-based, selenium, benzoyl peroxide
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AD: Symptomatic Tx
Shampoo Therapy
–Antibacterial/antifungal shampoos
–Soothing
–Barrier Repair
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AD: Symptomatic Tx
Shampoo Therapy
–Antibacterial/antifungal shampoos
FOR recurrent pyoderma/malassezia dermatitis
•MedidermÒ (piroctone olamine)
•Pyoben-S or PyohexÒ (chlorhexidine)
•MalasebÒ (chlorhex/miconazole)
–Soothing
–Barrier Repair
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AD: Symptomatic Tx
Shampoo Therapy
–Antibacterial/antifungal shampoos
–Soothing
•EpisootheÒ (oatmeal); AllergroomÒ (emollient)
•AloveenÒ (aloe vera/oatmeal)
•PAW sensitive skinÒ (no sulphates)
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AD: Symptomatic Tx
Shampoo Therapy
–Antibacterial/antifungal shampoos
–Soothing
–Barrier Repair
•NutridermÒ shampoo/conditioner
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AD: Symptomatic Tx
Moisturisers
–mainstay of symptomatic tx for AD in people
–rarely as effective in dogs, cats; important with
dry scaly skin
–Humectants
•attract water e.g. lactic acid, urea - non-oily
•prevent water loss e.g. propylene glycol, glycerine,
sorbolene
–Emollients
•fill spaces between kc’s with oil e.g. AllergroomÒ,
Alpha KeriÒ bath oil, other oils (almond, corn,
safflower, sesame), animal fats (lanolin),
hydrocarbons (mineral oil, paraffin oil, petrolatum)
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AD: Symptomatic Tx
Limit self trauma
•E-collar
•Body-suits
•Bandages
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AD: Symptomatic Tx
A.Safest Options
•Antihistamines
•Fatty acids
•Shampoos
•Moisturisers/Topical soothing products
•Limit self-trauma
A.Stronger Anti-inflammatories
•Topical GCs
•Systemic GC
•Cyclosporine
•Other
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AD: Symptomatic Tx
Topical Glucocorticoids
–mainstay of symptomatic tx for AD in
people
–may help minimally haired localised
areas
–more potent most effective: daily for
short periods; 1-2X wkly longer-term; may thin
skin and ­ risk infections
•AristocortÒ cream/oint (triamcinalone)
•EloconÒ lotion/cream/oint (mometasone)
•PanalogÒ oint (triamcinalone/neomycin)
•FucidermÒ gel (betamethasone/fusidic
acid)
•CortavanceÒ spray (hydrocortisone
aceponate)
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AD: Symptomatic Tx
Topical Glucocorticoids
–Less potent options with more transient effect
•Cort-Hex Ò, NeocortÒ (hydrocortisone) creams, lotions,
ointments
–Absorption best from moist skin
–Limit licking 10-mins after application
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AD: Symptomatic Tx
Systemic Glucocorticoids
–most effective, cheap, fast-acting option for severe
allergy flares (all) in many patients
–short-acting forms reasonably safe intermittently at low
doses if other options not effective
•severe steroid side-effects with even low-dose short-term
•high risk for side effects with long-term
•cats more resistant some steroid side effects cf. dogs – still can
be severe
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AD: Symptomatic Tx
Systemic Glucocorticoids
–Measures to ¯ risk side effects:
•Use short-acting only – often oral prednisolone
–for severe flares injectable formulations (e.g.
dexamethasone) more potent
•Restrict to low doses for longer-term use
–pred 0.1-0.2 (dogs) or 0.2-0.4 (cats) mg/kg eod or less
•Low regular dosing (pred £0.5mg 2X wkly) to hold
continual allergies at more comfortable level better
than repeated tapering courses
•Avoid long-acting preps (DepoMedrolÒ)
–Recommend safer alternatives, steroid-sparing
role
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AD: Symptomatic Tx
Cyclosporine
–Severe, poorly-responsive AD MUCH easier
•dogs + cats (off-label; oral solution in USA)
•including cases with recurrent 2º infections
–Potent immunosuppressive (more specific T-cells)
–No general body metabolic side effects
–Expensive!!
–Slower onset effect (2-5wks for good control)
–Doesn’t work for flea allergy, contact allergy
•ENSURE AD FIRST!
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AD: Symptomatic Tx
Cyclosporine
–Start 5mg/kg sid most; 7mg/kg cats, dogs <5kg
•Dose with food initially
–Continue until good control (by 6wks), then gradually taper in 2wk steps
•¯ dosing interval or daily dose
•typical maintenance dose 1-3mg/kg sid
–¯ dose & cost by:
•concurrent ketoconazole 5mg/kg bid or can combine to sid
–GIT signs (inappetance, vomiting) some patients
•concurrent grapefruit juice ? ~ 3-4 ice cubes/dog
•dose on empty stomach (after ¯ to lower doses)
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AD: Symptomatic Tx
Cyclosporine - Side effects (few):
–Diarrhoea most frequent, rarely severe; Vomiting (if no food)
• both more likely at higher doses
–Gingival hyperplasia, papillomatosis, hirsuitism - higher doses
–Unusual infections: fungal osteomyelitis; papillomas
–Fatal toxoplasmosis reported in cats
•FIV/FeLV first
•warn owners to act promptly if cat unwell (pyrexia?)
•no clear evidence prophylactic Ab’s (clindamycin, TMS) ¯ risk
•very rare, but increased risk cf. dogs
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AD: Treatment
1.Minimise allergen/irritant exposure
2.Immunotherapy
3.Symptomatic tx
1.Acute Flare Plan
2.Longer-term Management Plan
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