Veterinary consultancy content from SASH

1. Atopic Dermatitis
Linda Vogelnest BVSc MACVSc FACVSc

2. www.sashvets.com
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
2

3. www.sashvets.com
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
3

4. www.sashvets.com
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)
4
Microbes,
allergens
Water

5. www.sashvets.com
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”)
5
Microbes, allergensWater

6. www.sashvets.com
Atopic Dermatitis
• Atopy = broad allergic group
• Humans
– allergic rhinitis
– allergic asthma
– atopic dermatitis (eczema, AD)
• Dogs/Cats – AD most common
6

7. 7

8. 8

9. 9

10. 10

11. 11

12. 12

13. 13

14. 14

15. 15

16. www.sashvets.com
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
16
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.

17. www.sashvets.com
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
17

18. www.sashvets.com
AD: Treatment
1. Minimise irritant exposure
– variety of factors
• grass
• certain fabrics: wool
• heat
• dryness
• shampoos (rarely)
18

19. www.sashvets.com
AD: Treatment
1. Minimise allergen/irritant exposure
2. Immunotherapy
– requires skin test (or allergen-specific IgE serum test) → id
allergens
19

20. www.sashvets.com
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
20

21. www.sashvets.com
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
21

22. www.sashvets.com
AD: Treatment
1. Minimise allergen exposure
2. Immunotherapy
3. Symptomatic tx
22

23. www.sashvets.com
AD: Treatment
1. Minimise allergen exposure
2. Immunotherapy
3. Symptomatic treatment
1. Acute flare plan
2. Long-term management plan
23
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
24

25. www.sashvets.com
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
25

26. www.sashvets.com
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
26

27. www.sashvets.com
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
27

28. www.sashvets.com
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?
28

29. www.sashvets.com
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
29

30. www.sashvets.com
AD: Symptomatic Tx
Shampoo Therapy
– Antibacterial/antifungal shampoos
– Soothing
– Barrier Repair
30

31. www.sashvets.com
AD: Symptomatic Tx
Shampoo Therapy
– Antibacterial/antifungal shampoos
FOR recurrent pyoderma/malassezia dermatitis
•Mediderm® (piroctone olamine)
•Pyoben-S or Pyohex® (chlorhexidine)
•Malaseb® (chlorhex/miconazole)
– Soothing
– Barrier Repair
31

32. www.sashvets.com
AD: Symptomatic Tx
Shampoo Therapy
– Antibacterial/antifungal shampoos
– Soothing
• Episoothe® (oatmeal); Allergroom® (emollient)
• Aloveen® (aloe vera/oatmeal)
• PAW sensitive skin® (no sulphates)
32

33. www.sashvets.com
AD: Symptomatic Tx
Shampoo Therapy
– Antibacterial/antifungal shampoos
– Soothing
– Barrier Repair
• Nutriderm® shampoo/conditioner
33

34. www.sashvets.com
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. Allergroom®,
Alpha Keri® bath oil, other oils (almond, corn,
safflower, sesame), animal fats (lanolin),
hydrocarbons (mineral oil, paraffin oil, petrolatum)
34

35. www.sashvets.com
AD: Symptomatic Tx
Limit self trauma
• E-collar
• Body-suits
• Bandages
35

36. www.sashvets.com
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
36

37. www.sashvets.com
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
• Aristocort® cream/oint (triamcinalone)
• Elocon® lotion/cream/oint (mometasone)
• Panalog® oint (triamcinalone/neomycin)
• Fuciderm® gel (betamethasone/fusidic
acid)
• Cortavance® spray (hydrocortisone
aceponate)
37

38. www.sashvets.com
AD: Symptomatic Tx
Topical Glucocorticoids
– Less potent options with more transient effect
• Cort-Hex ®, Neocort® (hydrocortisone) creams, lotions,
ointments
– Absorption best from moist skin
– Limit licking 10-mins after application
38

39. www.sashvets.com
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
39

40. www.sashvets.com
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 (DepoMedrol®)
– Recommend safer alternatives, steroid-sparing
role
40

41. www.sashvets.com
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!
41

42. www.sashvets.com
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)
42

43. www.sashvets.com
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
43

44. www.sashvets.com
AD: Treatment
1. Minimise allergen/irritant exposure
2. Immunotherapy
3. Symptomatic tx
1. Acute Flare Plan
2. Longer-term Management Plan
44

45. 45

46. www.sashvets.com.au twitter: @SASHvets
Phone - (02) 9889 0289 Fax - (02) 9889 0431
Level 1, 1 Richardson Place, North Ryde 2113, Sydney, NSW