What is atopy and what are its symptoms?

Atopy, or environmental allergy, is an allergic reaction to airborne substances like pollen, molds, house dust mites and animal dander (skin or hair fragments). It is most common in dogs, but some cats are also affected. The incidence of atopy depends as much upon a pet’s genetic susceptibility as exposure to the allergen itself. (An allergen is any agent causing the allergic reaction.) Terriers, Setters, Retrievers, Dalmatians, and Chinese Shar-Peis are particularly prone to atopy.

Itching, mostly around the face, feet, lower chest and belly, is the primary symptom. Depending on the cause, this may occur only seasonally (pollen) or year-round (molds, dust mites and dander). “Hot spots”, other skin infections and ear problems can develop. Frequent scratching due to chronic irritation may lead to hair loss. These signs can be seen from 4 months to 7 years of age but are typically first noticed around 1–3 years of age.

How is atopy diagnosed?
Atopy is confirmed through a process of elimination. Other causes of itching, such as fleas, mites, lice, bacterial and yeast infections, as well as food allergies, must be ruled out first. Your veterinarian will ask you for a detailed history of your pet’s itching problem. Skin or serum (blood) testing for different allergens may then be performed to help pinpoint the exact cause.