Most Homes Harbor Multiple Allergens Interview with:

Dr. Salo

Dr. Salo

Dr. Pӓivi Salo, PhD Epidemiologist
National Institute of Environmental Health Sciences
NIH What is the background for this study?

Response: Indoor allergens are important risk factors for asthma and respiratory allergies. Only a few studies have investigated residential allergen exposures on a national scale; the National Health and Nutrition Examination Survey (NHANES) 2005-2006 is the largest and most comprehensive study to date. What are the main findings?

Response: Our findings show that exposure to multiple allergens is common in U.S. homes; over 90% of homes had three or more detectable allergens, and 73% of homes had at least one allergen at elevated levels. The presence of pets and pests contributed strongly to elevated allergen levels. Housing characteristics also mattered – elevated exposure to multiple allergens was more likely in mobile homes, older homes, rental homes, and homes in rural areas. For individual allergens, exposure levels varied greatly with age, sex, race, ethnicity, and socioeconomic status. Differences were also found between geographic locations and climatic conditions. What should clinicians and patients take away from your report?

Response: Understanding factors that affect allergen levels in homes is important because elevated allergen levels can trigger and exacerbate symptoms in people who suffer from asthma and allergies. We hope that our findings provide beneficial information to a wide audience from patients to clinicians, identifying factors that influence levels of exposure to individual and multiple allergens What recommendations do you have for future research as a result of this study?

Response: The relationships between allergen exposures, allergic sensitization, and disease are complex. Further research is needed to determine how allergen exposures interact with other environmental and genetic factors that contribute to asthma and allergies. Is there anything else you would like to add?

Response: We also compared allergen exposures and previously reported allergic sensitization patterns from this national survey to provide a more complete picture. The allergy focused component in NHANES 2005-2006, which we developed in collaboration with the National Institute of Allergy and Infectious Diseases (NIAID) and the Centers for Disease Control and Prevention (CDC), allowed national comparisons for the first time. The observed differences and overlaps reflect the complex nature of the relationships between allergen exposures, allergic sensitization, and disease. Thank you for your contribution to the community.


Salo P, Wilkerson J, Rose KM, Cohn RD, Calatroni A, Mitchell HE, Sever ML, Gergen PJ, Thorne PS, Zeldin DC. 2017. Bedroom allergen exposures in US households. J Allergy Clin Immunol; doi: 10.1016/j.jaci.2017.08.033(link is external) [Online 30 November 2017].

Note: Content is Not intended as medical advice. Please consult your health care provider regarding your specific medical condition and questions.


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Last Updated on December 4, 2017 by Marie Benz MD FAAD