Allergy Symptoms and Causes

Allergies are a result of an overreaction of a person's immune system. People with allergies have a hyper-alert immune system that overreacts to substances in the environment called "allergens". Normally harmless substances, such as pollen, can cause the immune system of allergic people to react as it was harmful to the body.

About 20% of all Americans have at least one allergy.

What Occurs During an Allergic Reaction?

When a person with an overreactive immune system is exposed to an allergen, a chain of events is set into motion:

1. The body produces a specific type of antibody, called IgE, to combat the allergen.
2. These antibodies attach themselves to mast cells (a type of blood cell). Mast cells are plentiful in the airways and the gastrointestinal tract, where allergens tend to enter the body.
3. The mast cells then explode, which releases a variety of chemicals including histamines, which cause the familiar runny nose, itchiness, etc.

What Are the Symptoms of Allergies?

Allergy symptoms are categorized as mild, moderate, or severe (anaphylactic).

• Mild reactions are isolated to one part of the body and include rashes, watery eyes, and congestion.
• Moderate reactions include symptoms that spread to other parts of the body. Itchiness or difficulty breathing are typical.
• A severe reaction (anaphylaxis), is a life-threatening emergency in which the response to the allergen is intense and affects the entire body. It often begins with itching of the eyes or face and progress within minutes to more serious symptoms, including abdominal pain, cramps, vomiting, and diarrhea. Swellings can make breathing and swallowing difficult. Confusion or dizziness may also occur because anaphylaxis also causes blood pressure to drop quickly.

No. People inherit a tendency to be allergic from their parents. If one parent is allergic, then a child has a 50% chance of inheriting this allergic tendency. Should both parents be allergic then there is a 75% of a child being allergic as well.