Allergies are the result of inappropriate immune responses to normally harmless substances. Allergy symptoms vary widely, from the sneezing, watery eyes, and nasal congestion of mild “hay fever” to severe rashes, swelling, and shock. Asthma is a chronic inflammation of the lungs that airborne allergens can trigger in susceptible people; tobacco smoke, air pollution, viral respiratory infections, or strenuous exercise can also contribute.
Allergies are the sixth leading cause of chronic disease in the United States and cost the healthcare system $18 billion annually.19 About half of all Americans test positive for at least 1 of the 10 most common allergens:20
- Bermuda grass
- Rye grass
- White oak
- Russian thistle
- Alternaria mold
- House dust mite
- German cockroach
Food allergy occurs in 6 to 8 percent of children age 6 years or younger and in 2 percent of adults.21 Common food allergens include:
- Cow’s milk
- Nuts. Peanuts and tree nuts are the leading causes of fatal and near-fatal food allergy reactions.
The prevalence of asthma is also high. For reasons that are still unclear, the prevalence of both allergy and asthma in the United States is increasing.
- In 2005, 30 million people living in the United States had asthma, resulting in more than 480,000 hospitalizations and approximately 4,200 deaths.
- In 2002, the asthma prevalence among non-Hispanic African Americans was approximately 30 percent higher than among non-Hispanic whites, and approximately double the level among Hispanics.
- Among individual race/ethnic groups, Puerto Ricans have the highest levels of asthma prevalence and asthma attack prevalence.
19 American Academy of Allergy, Asthma and Immunology (AAAAI). The Allergy Report. Available from: http://www.aaaai.org/ar/default.stm.
20 Matricardi PM et al. Hay fever and asthma in relation to markers of infection in the United States. J Allergy Clin Immunol. 110:381-387 (2002).
21 Sampson H. Peanut allergy. N Engl J Med. 346:1294-1299 (2002).