More Than Half the U.S. Population is Sensitive
to One or More Allergens
More than fifty percent of the U.S. population tested positive to
one or more allergens, according to a large national study. The new
findings, based on data from the third National Health and Nutrition
Examination Survey (NHANES III), shows that 54.3% of individuals
aged 6-59 years old had a positive skin test response to at least
one of the 10 allergens tested. The highest prevalence rates were
for dust mite, rye, ragweed, and cockroach, with about 25% of the
population testing positive to each allergen. Peanut allergy was the
least common, with 9% of the population reacting positively to that
food allergen.
The new findings published in the August issue of the Journal
of Allergy and Clinical Immunology were conducted by
researchers at the National Institute of Environmental Health
Sciences (NIEHS) and the National Institute of Allergy and
Infectious Diseases, both components of the National Institutes of
Health.
A positive skin test result may mean the individual is more
vulnerable to asthma, hay fever, and eczema. “Asthma is one of the
world’s most significant chronic health conditions,” said David A.
Schwartz, MD, the NIEHS Director. “Understanding what may account
for the rising worldwide asthma rates will allow us to develop more
effective prevention and treatment approaches.”
NHANES III is a nationally representative survey conducted by the
Centers for Disease Control and Prevention between 1988-1994 to
determine the health and nutritional status of the U.S. population.
Approximately 10,500 individuals participated in the skin testing.
During these tests, skin was exposed to allergy-causing substances
(allergens) and a positive test was determined by the size of the
reaction on the skin. The 10 allergens tested include: Dust mite, German
cockroach, cat, perennial rye, short ragweed, Bermuda grass,
Russian thistle, White oak, Alternia alternata, and
peanuts.
Researchers also compared skin test responses between NHANES III
and the previous survey, NHANES II, conducted from 1976-1980. The
prevalence of a positive skin test response was much higher in
NHANES III than in NHANES II.
According to the lead author, Samuel J. Arbes, Ph.D. of NIEHS,
“An increase in prevalence is consistent with reports from other
countries and coincides with an increase in asthma cases during that
time.” In the U.S., the prevalence of asthma increased 73.9% from
1980 to 1996. However, Dr. Arbes was quick to point out that
differences in skin test procedures between the two surveys prevent
the authors from definitively concluding that the prevalence of skin
test positivity has increased in the U.S. population.
“There is still much we don’t understand about why some people
become sensitized to allergens and others do not,” said Darryl C.
Zeldin, MD, senior author on the paper. “Much more research is
needed in order for us to understand the complex relationships
between exposures to allergens, the development of allergic
sensitization, and the onset and exacerbation of allergic diseases
such as asthma.”
The researchers recently added an allergy component to NHANES
2005-2006. In addition to the other NHANES data collection
components, dust samples from the homes of 10,000 individuals are
being analyzed for allergens, and blood samples taken from these
individuals are being examined for antibodies to those allergens.
This new NHANES 2005-2006 allergy component will allow researchers
to gain a greater understanding of asthma and the roles that indoor
allergens play in asthma and other allergic diseases.
NIEHS, a component of the National Institutes of Health,
supports research to understand the effects of the environment on
human health. NIAID supports basic and applied research to prevent,
diagnose and treat infectious diseases such as HIV/AIDS and other
sexually transmitted infections, influenza, tuberculosis, malaria
and illness from potential agents of bioterrorism. NIAID also
supports research on transplantation and immune-related illnesses,
including autoimmune disorders, asthma and allergies. For more
information about allergens and other environmental health topics,
please visit the NIEHS website at http://www.niehs.nih.gov/ or the NIAID website at
http://www.niaid.nih.gov/.
The National Institutes of Health (NIH) — The Nation's Medical
Research Agency — is comprised of 27 Institutes and Centers and
is a component of the U. S. Department of Health and Human Services.
It is the primary Federal agency for conducting and supporting
basic, clinical, and translational medical research, and
investigates the causes, treatments, and cures for both common and
rare diseases. For more information about NIH and its programs,
visit www.nih.gov.
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