Allergen specific immunotherapy (ASIT) for atopic dermatitis (pollen, dust and mould)

Diagnosis of atopic dermatitis

Atopic dermatitis in dogs, cats and horses is diagnosed by history, physical examination, and ruling out other causes of pruritus, especially adverse food reactions and ectoparasites.

Atopic dermatitis is then definitively diagnosed by intradermal allergy testing (IDAT) or serologic tests (ELISA) evaluating for allergen-specific IgE.

Intradermal allergy testing (IDAT) or serologic tests (ELISA)

IDAT is still considered to be the “gold standard” for the diagnosis of atopic dermatitis but the comparable efficacy of IDAT versus in vitro serologic testing in atopic individuals remains controversial.

It is important to note that intradermal testing and in vitro serology are measuring different things (fixed tissue IgE vs circulating antigen specific IgE) and that serum IgE does not necessarily correlate with cutaneous IgE levels and skin reactivity.

10 to 15% of clinically atopic dogs have negative intradermal and in vitro serologic tests that cannot be explained by false negative reactions.

There is data to suggest that the utilisation of both tests together in screening for offending allergens may improve overall success of immunotherapy and this has been our experience.

By performing both tests we can identify the complete allergy profile for the patient and this increases our chances of successful vaccine immunotherapy for your patients. For more information on atopic dermatitis see this link (link to atopic dermatitis info)

What is involved in ASIT and how much does it cost?

ASIT involves the subcutaneous injection of gradually increasing doses of relevant allergens over a period of time until a maintenance dose is reached.

The treatment is thought to work by correcting the imbalance in the patient’s T lymphocyte populations with the net effect that interleukin 4 secretion is reduced.

Download our current immunotherapy protocol. (pdf format)

Rush Immunotherapy

There is some recent data to suggest that "rush" immunotherapy (all of the initial, gradually increasing dosage and frequencies of shots given in one day) may hasten the onset of benefit of ASIT and may result in an overall increased incidence of success.

See more information on rush immunotherapy (pdf format) in the Skin, Allergy and Ear Clinic.

Effectiveness and fees

Allergen avoidance and ASIT are the only specific treatment available to allergic patients. It is effective in about 70% of the dogs treated at the Skin, Allergy and Ear Clinic at Murdoch University and 70-80% of the cats.

ASIT requires a significant amount of clinician to pet owner communication, especially so that the pet owner understands:

• ASIT will take 6 to 12 months before it begins to help.
• If effective, the treatment will need to be continued for between 3 to 5 years.
• If effective, the patient may still need ancillary treatment (antibiotics, antihistamines, fatty acids, topical therapy etc).
• An allergy vaccine costs between $500 to $600 (Aus) per year.