Skin Testing

What is skin testing?

Skin Testing

Intradermal Testing

Intradermal testing (IDT) or allergy skin testing is a tool that aids the dermatologist in the selection of environmental allergens (pollen, mold, mites, insects, dander) for subsequent immunotherapy (allergen-specific allergy shots). This test followed by tailor-made allergy shots is best performed after other possibilities for the itchy skin disease have been excluded. Veterinary IDT is similar to human allergy skin testing; however, our patients need sedation and clipping. The side of the chest will be shaved in the shape of a rectangle and small black Sharpie pen dots will be put in a linear array on the shaved skin allowing us to know where to make each injection. A panel of allergens is then injected in the skin. The size of any developing wheals is recorded. The entire procedure last approximately 30 minutes. Importantly, this test is used for environmental allergies (atopic dermatitis), not food-related allergies.

What medications need to be discontinued prior to skin testing?

There are several medications prescribed for itchy skin that will inhibit (wheals) on allergy skin testing. Please keep in mind this is a rough guideline; individual cases may vary. Review the drug withdrawal schedule below and discuss it with your primary care veterinarian. Drugs are to be withdrawn under the advice and discretion of your primary care veterinarian.

Topical steroids (ears, skin, or eyes) 15-30 days (2-4 weeks)
Oral steroids 30-60 days (4-8 weeks)
Injectable steroids 70-84 days (10-12 weeks)
Topical or oral antihistamines 10-14 days (2 weeks)
Fatty acid supplementation (if possible) 14-21 days (2-3 weeks)
Tranquilizers 2-3 days (0.5 weeks)
Cyclosporine Case by case basis

What medications can I continue to give my pet prior to skin testing?

Antibiotics, antifungals, flea prevention, heartworm prevention, insulin, thyroid supplementation, heart medication, anti-seizure medication, and ophthalmic cyclosporine/tacrolimus for dry eye can be continued prior to any appointment or skin testing procedure. Cool water baths with oatmeal can be used to help soothe the skin and relieve itch up to 3 days before skin testing. Ears may be flushed with a veterinarian-recommended flushing agent. Please discuss what medications you should continue administering prior to the appointment with your primary care veterinarian in the event your pet has not yet been examined by the dermatologist.