Intradermal Allergy Testing (IDAT)
Canine atopic dermatitis is a clinical diagnosis, which is established upon ruling out or controlling other similar skin disorders such as cutaneous adverse food reaction and flea allergy dermatitis. Feline atopy (non-flea, non-food allergic dermatitis) follows similar principles of diagnosis. The diagnosis should always precede allergy testing. Intradermal allergy testing is recognized by most veterinary dermatologists as the most accurate means of identifying relevant allergens in the canine patient. Dr. Bajwa most often utilizes the intradermal allergy testing in canine as well as feline patients due to the benefits of in vivo testing, and few drawbacks of the test. Dr. Bajwa has had significant success utilizing intradermal allergy testing to help treat non-flea, non-food allergic dermatitis in cats.
Serum-based allergy testing has also been documented to be beneficial as part of a through dermatologic work up for an atopic patient. In some patients, benefits of both intra-dermal allergy testing and serum allergy testing may need to be combined in order to obtain maximal information that will help formulate a successful therapeutic plan for an environmentally allergic patient.
Approximately 60 of the most common allergens specific to our local environment are assessed during intra-dermal testing. Board-certified veterinary dermatologists generally offer intradermal allergy testing as they often tackle and manage allergic skin disease in pets. Common allergen classes that are assessed during allergy testing include house dust mites, tree pollen, grass pollen, weed pollen, and environmental moulds. Various combinations of allergens can also be tested utilizing serum-based allergy tests. Many local diagnostic laboratories supply a variety of serum allergy tests.
Guidelines on Preparing a Patient for the Intradermal Allergy Testing Procedure:
The following medication washout periods prior to intradermal allergy test and serum-based allergy testing are generally suggested:
- Injectable steroids (long-acting) – 90 days
- Oral steroids including Vanectyl P, Prednisone, etc. – 30 days
- Steroidal skin, ear, and eye ointments (topical therapy) – 14 days
- Antihistamine medications (Benadryl, Reactine, etc.) – 7 days
- Tranquilizers including Acevet, Atravet, Clomicalm – 7 days
- Oral & topical essential fatty acids including fish oils – 7 days
- Medicated baths – 5 days
The following medications do not generally need to be discontinued prior to allergy testing:
- Flea Preventive Medications
- Atopica (Cyclosporine)
- Thyroid Medications
- Anti-Seizure Medications
- Cardiac Medications