MADISON, N.J., May 25, 2011 /PRNewswire/ -- A study of nearly 14 million blood tests for aiding allergy diagnosis shows that men exhibited higher sensitivity to 11 common allergens than women when tested, contradicting other research suggesting women experience allergies more frequently than men. The study's findings raise the possibility that men have a higher risk for allergies than women or that men, as a function of their gender, require different reporting standards when evaluated for allergies with increasingly used blood tests.
The Quest Diagnostics Health Trends™ Report, Allergies Across America™, from Quest Diagnostics (NYSE: DGX), is the largest study ever conducted on allergy testing in order to assess allergy trends in the United States. The study evaluated results of ImmunoCAP® specific Immunoglobulin E (IgE) blood testing to 11 common allergens, including common ragweed and mold, two dust mites, cats and dogs and five foods. IgE is an antibody in blood produced by the body's immune system when an allergen is present. A high IgE sensitization level for a specific allergen tested is highly suggestive of an allergy, although physicians also evaluate symptoms, medical history and other factors in order to clinically diagnose an allergy.
"This landmark report, based on testing of patients in every state of the country and the District of Columbia, underscores that allergies are a major public health concern, and that gender, age and region influence their impact on the health of Americans," said Surya N. Mohapatra, Ph.D. chairman and chief executive officer, Quest Diagnostics.
Earlier this month, Quest Diagnostics released preliminary results from the report, including growth rates of two environment-based allergens linked to climate change and associations between allergies and asthma in children. Allergies are one of the most common health conditions, affecting one in five Americans.
To access the full report, released today, visit QuestDiagnostics.com/HealthTrends.
Gender and Allergen Sensitivity
High sensitization rates correlate with increased allergy risk or allergy symptoms at different ages, and physicians consider sensitization levels when evaluating a patient for an allergy. In the Quest Diagnostics study, the combined IgE allergen sensitization rate for the 11 allergens evaluated in the study was approximately 10% higher for men than for women at all ages. The findings contradict other research, including a meta-analysis of 591 studies that found that women make up 65% of adults identified with allergies.
"Our study suggests that allergies in men may not be less prevalent than in women, as suggested by other research, and men may be at risk for underdiagnoses of allergies," said study investigator Stanley J. Naides, M.D., medical director, Immunology, Quest Diagnostics. "Additional research will determine whether men truly are at greater allergy risk or simply experience higher sensitization rates as a result of their gender, a finding which could affect physicians' interpretation of increasingly used IgE blood tests."
The Quest Diagnostics study found that IgE blood testing has increased dramatically in physician practices, with primary care physicians newly adopting the ImmunoCAP test more than twice as fast as allergists (49% growth in ordering versus 23%).
Risk of Allergy Misdiagnosis
In addition, the study found that about half of patients tested (5 in 9) did not show sensitization to at least one of 11 common allergens evaluated. While the investigators hypothesized that some of these patients had an allergy to one or more allergens not evaluated in the study, they also theorized that a large number may have presented to their physician with allergy-like symptoms caused by a non-allergy medical condition. The Asthma and Allergy Foundation of America (AAFA) reported this month that about 51% of patients suffering from allergy symptoms acknowledged in a survey that they had misdiagnosed their sinusitis as allergies.
"As our study and the recent survey by AAFA demonstrates, physicians and patients should exercise caution in concluding an allergy exists based on allergy-associated symptoms," said study investigator Harvey W. Kaufman, M.D., senior medical director, Quest Diagnostics. "We suspect that some people assume their runny nose, coughing and other symptoms are due to allergies, when this may not be the case. Appropriate evaluation by a physician may reveal another medical condition which, if accurately diagnosed, may be treatable."
Methodology of the Quest Diagnostics Health Trends Report Allergies Across America
The Allergies Across America study is broadly representative of the overall population of patients seeking medical care for allergy-like symptoms from healthcare professionals in the U.S. It includes de-identified test results of patients from infancy to 70 years of age living in every U.S. state and the District of Columbia. The study examined testing over a four-year period. It did not track individual patients longitudinally. It is based on de-identified results of testing in Quest Diagnostics clinical laboratories in the United States using the ImmunoCAP® specific IgE blood test, the "gold standard" of allergy blood tests, from Sweden-based Phadia AB.
About Quest Diagnostics Health Trends Reports
Quest Diagnostics Health Trends Reports identify and track disease and wellness benchmarks. Based on analyses of de-identified test results from the Quest Diagnostics national database – consisting of more than 1.5 billion patient encounters since January 2000 – past reports have focused on chronic kidney disease, diabetes, heart disease, H1N1 (2009) Influenza A, and rotavirus. Visit QuestDiagnostics.com/HealthTrends.
About Quest Diagnostics
Quest Diagnostics is the world's leading provider of diagnostic testing, information and services that patients and doctors need to make better healthcare decisions. The company offers the broadest access to diagnostic testing services through its network of laboratories and patient service centers, and provides interpretive consultation through its extensive medical and scientific staff. Quest Diagnostics is a pioneer in developing innovative new diagnostic tests and advanced healthcare information technology solutions that help improve patient care. Additional company information is available at: www.QuestDiagnostics.com.
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