What are allergies?
An allergy is an abnormal or exaggerated reaction of the immune system to a substance, which, in the majority of people causes no symptoms at all. The substance that triggers the allergy is known as an allergen. Common allergens include pollens, pet dander, molds, dust mites, foods, insect venoms and drugs. There are different types of allergic mechanisms. Some can be immediate and some can be delayed. Allergic reactions can affect your nose, throat, eyes, lungs, skin, stomach or intestines. Rarely, they can affect the whole body. Whenever you are exposed to something you are allergic to, your body will trigger an allergic response again. That is why it's important to know what you are allergic to and take steps to treat or avoid a reaction.
Different types of allergies include allergic rhinitis, allergic conjunctivitis (eye allergies) food allergies, insect venom allergies, latex allergies, contact dermatitis (skin allergies) and drug allergies. Asthma, eczema (atopic dermatitis) and hives can be associated with allergies.
How are allergies diagnosed?
The diagnosis of allergy can be complicated and involves the combination of a thorough history and appropriate allergy testing. A good history is very important and is one reason we have such a thorough new patient questionnaire form. There are different types of allergy tests depending on the type of allergy symptoms you are having.
Prick tests – This is the most common allergy test. In this test a tiny drop of the possible allergen is pricked or scratched into the skin. If you are allergic to this allergen you will develop a small hive like reaction at the site. Allergy prick skin testing is the most accurate and preferred method of evaluating allergies.
Intradermal test - This test is usually used in testing to things such as insect stings and penicillin. It is sometimes used for pets, dust mites and pollen testing if the prick test to these allergens is negative. A small amount of the possible allergen is injected under the skin through a thin needle, similar to a TB skin test.
Patch testing – This test is used to determine contact skin allergies, such as nickel, fragrance, lanolin, etc. It is also used in certain type of food allergies. For this test a small amount of the allergen is placed on a patch on your back. It stays in place for two days then is read the following day. This requires appointments on Monday, Wednesday and Thursday of the same week.
Blood tests – IgE blood testing (immunocap) is available and may help determine some food and environmental allergies. There is no blood test that can replace the patch test.
How are allergies treated?
Once we have identified the allergens that are causing your symptoms, an effective treatment plan can be recommended. These treatment plans include:
Avoidance of allergens
Immunotherapy / Allergy shots
Your allergist can discuss these options with you to determine your best treatment plan.
Food Allergy Websites
Types of Allergies