46. Atopy Flashcards

1
Q

Canine atopic dermatitis?

A

Genetically inherited predisposition to anaphylactic or allergic

diseases

CANINE ATOPIC DERMATITIS (CAD)

Common skin disorder; Hereditary disposition to develop pruritic

inflammatory skin disease associated with IgE antibodies (which

typically target environmental allergens)

Predisposed: Dogs > Cats; 6 months – 3 years

West Highland White Terrier; Labrador; German Shepherd and many

more…

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2
Q

Feline atopy?

A

FELINE ATOPY

Clinical signs

§ Generalised pruritis § Facial pruritis

§ Miliary dermatitis-like lesions § Pruritic ears

§ Symmetric alopecia § Indolent ulcer

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3
Q

Pathogenesis and allergens?

A

PATHOGENESIS

  1. Percutaneous sensitisation to environmental allergens

and/or allergens from food

  1. Induced skin infiltration by various inflammatory cells
  2. Activation of resident cells
  3. Local production of inflammatory/itch mediators

ALLERGENS

Ectoparasites: Fleas

Environmental factors:

§ Mites § Fungi

§ Dander § Mould

§ Pollen § Feathers

Cutaneous bacterial colonisation or infection

Epidermal barrier dysfunction

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4
Q

Forms and clinical signs?

A

FORMS:

§ Atopic dermatitis (most common)

§ Atopic rhinitis

§ Atopic conjunctivitis

CLINICAL SIGNS

§ Pruritis § Erythema

§ Secondary skin lesion § Pyoderma

§ Seborrhoea § Papules

§ Lichenification

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5
Q

Diagnosis?

A

DIAGNOSIS

It is important to exclude other differential diagnoses

If you suspect canine atopic dermatitis, you should establish:

§ The age of onset

§ Seasonality of clinical signs

§ Pruritis with no skin changes at onset

§ Family/breed disposition

§ Previous response to glucocorticoids

Allergy testing

Not to be used for diagnosing CAD

§ Intradermal skin testing

§ IgE testing

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6
Q

Criteria for atopy?

A

CRITERIA FOR ATOPY

Favrot’s criteria (2010)

These criteria have a sensitivity & specificity of 80% when 5 out of 8

are fulfilled. Therefore this should be performed concurrently with

the previously mentioned and other diagnostics to avoid

misdiagnosis.

Onset of signs < 3 years of age

Dog living mostly indoors

Glucocorticoid-responsive pruritis

Pruritis sine materia at onset (Ø associated causal dermatosis)

Affected front feet

Affected ear pinnae

Non-affected ear margins

Non-affected dorsolumbar area

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7
Q

Treatment?

A

TREATMENT

CAD Requires a multimodal treatment approach to ↓ pruritis & inflammation

§ First identify & address the associated flare factors:

§ Fleabite hypersensitivity § Fleas

§ Bacterial overgrowth § Yeast overgrowth

§ Environmental allergens § Food allergens

§ Topical and/or systemic treatment ↓ pruritis &

Inflammation

Symptomatic

§ Glucocorticoids: Prednisolone (long term)

§ Cyclosporine

§ Apoquel (oclacitinib)

Topical: Shampoo; Spray; Spot-on; Cream; Gel

Other

§ Antihistamine

§ Vitamins

§ Essential FAs

§ Non-specific immunotherapy

§ Desensitisation – Allergy vaccines (mitigation rather than

treating)

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