Allergies are the body's unusual excessive immune responses to foreign substances. that can be harmful. Typically, the immune system protects the body from harmful germs, such as bacteria and viruses. But the immune system in some individuals can react to substances called allergens that do not affect others. As many as 50 million Americans have some type of allergy each year.
There are several different types of allergies that affect people, including:
- Food allergies, which can cause severe reactions when eating a trigger food. Common foods that cause allergies are peanuts, eggs, cow's milk, fish, shellfish, soy, wheat, and tree nuts (with peanuts as the most common).
- Skin allergies such as those that result in eczema, hives, and contact dermatitis...