What is Allergy?

A misguided reaction to foreign substances by the immune system , the body system of defense against foreign invaders, particularly pathogens(the agents of infection). The allergic reaction is misguided in that these foreign substances are usually harmless. The substances that trigger allergy are called allergen.

Although allergies can develop at any age, the risk of developing allergies is genetic. It is related to one’s family history of allergy. If neither parent is allergic, the chance for allergies is about 15%. If one parent is allergic, the risk increases to 30% and if both are allergic, the risk is greater than 60%.

Types of allergens:

Allergens are substances that can cause an allergic reaction. There are three primary types of allergens:

• Inhaled allergens affect the body when they come in contact with the lungs or membranes of the nostrils or throat. Pollen is the most common inhaled allergen.
• Ingested allergens are present in certain foods, such as peanuts, soy, and seafood.
• Contact allergens must come in contact with your skin to produce a reaction. An example of a reaction from a contact allergen is the rash and itching caused by poison ivy.

How to prepare for allergy testing:

Before your allergy test, your doctor will ask you about your lifestyle, family history, and more.

They’ll most likely tell you to stop taking the following medications before your allergy test because they can affect the test results:

• prescription and over-the-counter antihistamines
• certain heartburn treatment medications, such as famotidine (Pepcid)
• anti-IgE monoclonal antibody asthma treatment, omalizumab (Xolair)
• benzodiazepines, such as diazepam (Valium) or lorazepam
• tricyclic antidepressants, such as amitriptyline (Elavil)