1. Examine the Environment
More often than not, the trigger for rhinitis is right under the patient's nose, literally. Allergens in the air, such as pet dander, mold, spores, pollen, dust and debris, can quickly and spontaneously lead to rhinitis or rhinitis-like symptoms. Similarly, cigarette smoke, pollution, certain types and concentrations of chemicals, and even some kinds of food can also lead to allergic rhinitis. Your first step in sleuthing out the cause is to remove offending agents from the environment. If your symptoms decrease on days when the pollen count is low, for instance, the trigger may indeed be tree pollen.
2. Take a Skin Test
If a simple examination of your environment doesn't yield a conclusive causal agent, you may want to try a skin test or "scratch test."ÂThis involves a doctor or nurse introducing small quantities of various allergens under the skin. Generally, this is done by scratching the skin in an unobtrusive place (on the back of the shoulder blade or under the arm) and slipping minute amounts of common allergens under the skin to watch for skin irritation or rhinitis-like reactions.
3. Laboratory Tests May Help
If your skin test still doesn't yield conclusive results, you may opt for a laboratory blood test. An allergy specialist can run a battery of tests on a blood sample to determine potential reactions with a host of more minor and less common allergens. A comprehensive blood test can be significantly more expensive than a simple skin test. Generally, your physician will look for your eosinophil count levels and levels of IgE serum.
4. Is There a Trigger at All?
At the end of the day, your rhinitis may not be caused by any individual allergen but instead may be the result of abnormally sensitive blood vessels in the nasal membrane. In this case, you may be diagnosed instead with vasomotor rhinitis, which presents with many of the same symptoms as allergic rhinitis but requires a slightly different course of treatment.
