An allergy is an abnormal immune reaction to substances that are ordinarily harmless. There are many ordinary substances that can trigger allergic reactions. Among the most common are pollens, molds, dust mites, animal dander, foods, medicines and insect stings. We get exposed to substances by inhaling them, ingesting them, or simply by having them come in contact with our skin. An allergic reaction may occur anywhere in the body, but usually appears in the skin, eyes, lining of the stomach, nose, sinuses, throat and lungs — places where special immune system cells are stationed to fight off invaders.

You should see an allergist if:

  • Your allergies are causing symptoms such as sinus infections, nasal congestion or difficulty in breathing.
  • You experience hay fever or other allergy symptoms several months out of the year.
  • Antihistamines and other over-the-counter medications do not control your allergy symptoms, or create bothersome side effects, such as drowsiness.
  • Your asthma or allergies interfere with your ability to carry on day-to-day activities.
  • Your asthma or allergies decrease the quality of your life.