Allergy and Asthma Information
When, for a prolonged period, you are exposed to and experience symptoms from an allergen to which you are sensitive, your nose becomes ‘primed’, that is, ready to respond to irritants or to other allergens to which you are normally less sensitive. This response could trigger an asthma attack. For instance, when you are having nasal symptoms during the ragweed season and you are then exposed to dust, the dust can trigger a worsening of your allergy and asthma symptoms even if you are normally not very sensitive to dust.
Allergic Appearance
People who have allergies often breathe through their mouths and frequently itch or rub their noses. Allergic children often rub their noses in an upward and outward manner, similar to a salute, which has been called the ‘allergic salute’. A crease may be present along the lower third of the nose as a result of the frequent rubbing of the nose to relieve the itch.
Dark circles may be present under the eyes, called ‘allergic shiners’, and the eyes may appear a little red. When the doctor looks inside your nose, the mucus membranes are swollen and ‘boggy’ and appear pale. If there is an infection in your nose, the appearance is quite different, as the mucus membranes are then reddened.
How Allergies Are Diagnosed
Allergies are dignosed by a medical history suggesting a seasonal pattern of a particular exposure that makes asthma and allergy symptoms worse. A review of your overall medical history and present medications allows your doctor to rule out other possibilities that may account for your symptoms. A careful physical examination is also important, looking for characteristic appearance of the inside of the nose and checking for subtle asthma symptoms.
Allergy Skin Tests
Allergy skin testing is performed to determine if someone is allergic. The doctor who performs the skin tests must carefully correlate the test results to the patient’s medical history, as it is possible on occasion to have falsely positive or negative test results. Allergy skin testing identifies whether the specific allergy antibody for the allergen being tested is present on mast cells found in the patient’s skin.
There are two ways to administer allergy skin tests - the scratch or prick test, and the intradermal test.
The prick technique involves placing a drop of an extract of the allergen (such as dust, dog fur, or ragweed pollen) on the skin, typically on the back or forearm. Allergens are placed on the skin in rows so that multiple tests can be performed at the same time. A lancet is then used to gently scratch or puncture the skin to introduce the allergin into the skin.
With the intradermal test, the allergen is injected in dilute form just under the skin to create a small bubble.