Your doctor may suspect a pet allergy based on symptoms, an examination of your nose, and your answers to his or her questions. He or she may use a lighted instrument to look at the condition of the lining of your nose. If you have a pet allergy, the lining of the nasal passage may be swollen or appear pale or bluish.
Allergy skin test
Your doctor may suggest an allergy skin test to determine exactly what you're allergic to. You may be referred to an allergy specialist (allergist) for this test.
In this test, tiny amounts of purified allergen extracts — including extracts with animal proteins — are pricked into your skin's surface. This is usually carried out on the forearm, but it may be done on the upper back.
Your doctor or nurse observes your skin for signs of allergic reactions after 15 minutes. If you're allergic to cats, for example, you'll develop a red, itchy bump where the cat extract was pricked into your skin. The most common side effects of these skin tests are itching and redness. These side effects usually go away within 30 minutes.
In some cases, a skin test can't be performed because of the presence of a skin condition or because of interactions with certain medications. As an alternative, your doctor may order a blood test that screens your blood for specific allergy-causing antibodies to various common allergens, including various animals. This test may also indicate how sensitive you are to an allergen.