Key Facts:
Allergy is defined as a “harmful, increased susceptibility to a specific substance,” also known as hypersensitivity, while immunity is characterized as a “protective, enhanced resistance.”
- Indoor allergens play a major role in allergic diseases such as asthma and perennial allergic rhinitis. Most Americans spend more than 20 hours indoors each day.
- Outdoor allergens (pollens) play a major role in seasonal allergy symptoms.
- People are exposed to allergens through inhalation, ingestion, contact with skin and injection.
- Viral upper respiratory infections can aggravate allergies.
Statistics:
- Estimates from a skin test survey suggest that allergies affect as many as 40 to 50 million people in the United States.
- Allergic diseases affect more than 20% of the U.S. population.
- Allergic diseases are the sixth leading cause of chronic disease in the United States.
- It is estimated that in 1998, increased absenteeism and reduced productivity due to allergies cost U.S. companies more than $250 million.
New Research:
- Dog and cat allergen is found in all homes in the United States (JACI July 2004; Samuel J. Arbes, Jr. DDS, MPH, PhD, et al).
- Allergen avoidance using school clothing or banning of pets reduces airborne cat allergen in classrooms (JACI June 2004; Karlsson, et al).