Allergy facts

An allergy is a hypersensitivity disorder of the immune system. Symptoms include red eyes, itchiness, and runny nose, eczema,hives, or an asthma attack. Allergies can play a major role in conditions such as asthma. In some people, severe allergies to environmental or dietary allergens or to medication may result in life-threatening reactions called anaphylaxis. Food allergies and reactions to the venom of stinging insects such as wasps and bees are more often associated with these severe reactions. Not all reactions or intolerances are forms of allergy.

• Allergy involves an exaggerated response of the immune system, often to common substances such as foods or pollen. 
• The immune system is an intricate system that defends the body against foreign invaders, such as bacteria and viruses, while also surveying for conditions such as cancer and autoimmunity. 
• Allergens are substances that are foreign to the body and can cause an allergic reaction. 
• IgE is the allergic antibody. 
• Allergies can not only develop at any age, but many individuals also outgrow allergies over time. 
• While environment plays a role in allergy development, there is a greater risk of developing allergic conditions if a person has a family history of allergy, especially in parents or siblings.