Learn About Allergies

What are allergies?
An allergy is an abnormal reaction by the immune system to a substance that is usually not harmful. The immune system protects the body from foreign substances (antigens) by producing antibodies to fight them. Normally, the immune system ignores harmless substances and fights only dangerous ones. A person develops an allergic reaction when the immune system mistakenly interprets a harmless substance as a harmful one and attacks the harmless substance with histamine. Histamine produces the bothersome symptoms associated with allergies. It is estimated that about 24 million Americans suffer from allergies.

What causes allergies to develop in the first place?
No one knows for sure what causes allergies to develop, but heredity may play a part. If both parents have allergies, their child is more likely to develop allergies than a child of one allergic parent. However, that child's allergies may not be to the same allergen as the parents. During your life, your allergies may flare up, subside and even go away all together.

What triggers allergies?
The most common substances that trigger allergies are:

What are the symptoms of allergies?
Symptoms of pollen, mold, dander and dust mite (respiratory) allergies include:

Symptoms of insect sting/bite allergies include:

Symptoms of latex allergies include:

What are common food allergies and symptoms?
Food allergies are most commonly attributed to milk, fish, shellfish, nuts, eggs, wheat and berries. Allergic reactions to these items can occur within just minutes of consumption.

Symptoms of food allergies include:

How are food allergies diagnosed?
To get an accurate diagnosis, the allergist must first determine if the allergic reaction is to a specific food. This determination can be made through a detailed patient history, a patient's "diet diary" or an elimination diet. A diet diary involves the patient keeping a record of each meal and whether or not a reaction occurred. An elimination diet involves the patient not consuming a food suspected of causing the allergy. If the food is removed, and the symptoms cease, that food is most likely the cause of the allergic reaction.

Once a specific allergy is suspected, either a skin test or lab work can be performed to confirm what substance is causing the reaction. Many of these tests can be done right in an allergist's office. Once the test is performed, the patient will wait for about 20 minutes to see what reactions they may have. The size of each reaction is then measured. These tests are easy to perform and cause very little discomfort.

What treatment options are available for food allergies?
Avoiding the allergy-causing food is the best treatment. However, once exposed, antihistamines or steroids are commonly used. In life-threatening allergic reactions (known as anaphylactic shock), an injection of epinephrine can help reverse symptoms.

What are common drug allergies and symptoms?
Medication allergies are most commonly caused by penicillin or aspirin. The symptoms, which can vary from mild to life-threatening, include skin rash, hives, congestion, itchy eyes, and swelling in the mouth and throat.

What treatment options are available for drug allergies?
Similar to food allergies, avoiding the allergy-causing medication is the best treatment. However, once exposed, antihistamines or steroids are commonly used. Drugs called bronchodilators may be used to combat coughing and congestion. And for life-threatening allergic reactions (known as anaphylactic shock), an injection of epinephrine can help reverse symptoms.