Allergies
Nearly one out of every five people in the United States suffers from some type of allergy. Allergies are caused by an immune system reaction to a substance in the environment. The particular substance—the allergen—can be different for each allergy sufferer, and the substances are typically harmless to those who do not have allergies. There are many common types of allergies. Quite a lot of people are allergic to pollen, for example. Other widespread allergens include mold, latex, milk, eggs, nuts, shellfish, wheat, bee stings, and pet dander. [...more]
