Official reprint from UpToDate®
www.uptodate.com ©2017 UpToDate, Inc. and/or its affiliates. All Rights Reserved.

Allergen sampling in the environment

Robert G Hamilton, PhD, DABMLI, FAAAAI
Section Editor
Peter S Creticos, MD
Deputy Editor
Anna M Feldweg, MD


Avoidance of allergens remains a cornerstone in the management of patients with allergic diseases. However, many allergens, such as those associated with dust mites, other insects, and animal danders, are ubiquitous in the environment and cannot be entirely avoided. Therefore, effective avoidance measures should be tailored to the specific allergens that are important for a particular patient. The clinician should also focus on environments that can be altered (ie, indoor spaces) and those in which the patient spends significant time. In this context, allergen sampling of the environment may be clinically useful.

This topic will discuss the identification of allergens, indications for allergen sampling, and methods for sampling and measuring allergens, with a focus on aeroallergens in the indoor environment. Indicators of quality testing methods that the clinician can use to identify an appropriate testing laboratory are also discussed. Testing of individuals to determine sensitivity to specific allergens and measures to reduce indoor allergen exposure are presented elsewhere. (See "Overview of skin testing for allergic disease" and "Allergen avoidance in the treatment of asthma and allergic rhinitis".)


An allergen is a natural substance that is generally innocuous to most people, but when introduced into a genetically-predisposed individual, elicits the formation of immunoglobulin E (IgE) antibodies specific to that substance. These allergen-specific IgE antibodies bind to IgE receptors on the surface of the individual's mast cells and basophils. When the subject is re-exposed to that allergen, the allergen binds multiple IgE molecules in the cells' surface, generating activation signals. Mast cell and basophil activation results in the release of an array of inflammatory mediators that precipitate the symptoms of allergic disease.

The identification of clinically-important allergens in an environment begins by obtaining clinical histories from affected individuals who, when exposed to a given substance, develop similar signs and symptoms that are known to represent IgE-mediated allergic disease. This process is undertaken when new allergens are suspected in a population. In the past few decades, several new allergens have been identified, such as Asian ladybugs and stink bugs, and new occupational allergens are regularly identified among manufacturing workers.

Making the connection between symptoms and a specific exposure is most straightforward when allergic symptoms appear shortly after exposure (eg, anaphylaxis following ingestion of peanuts, severe rhinitis or asthma following grass cutting). In contrast, allergens to which people are chronically exposed are much more difficult to identify. As an example, it took several decades to identify the dust mite as the primary source of allergenic material in house dust [1]. In addition, allergen dose and route of exposure also affect the clinical presentation [2]. Allergens that are inhaled or injected usually cause more immediate symptoms compared with those that are ingested.

To continue reading this article, you must log in with your personal, hospital, or group practice subscription. For more information on subscription options, click below on the option that best describes you:

Subscribers log in here

Literature review current through: Oct 2017. | This topic last updated: Apr 11, 2016.
The content on the UpToDate website is not intended nor recommended as a substitute for medical advice, diagnosis, or treatment. Always seek the advice of your own physician or other qualified health care professional regarding any medical questions or conditions. The use of this website is governed by the UpToDate Terms of Use ©2017 UpToDate, Inc.
  1. Spieksma FT, Dieges PH. The history of the finding of the house dust mite. J Allergy Clin Immunol 2004; 113:573.
  2. Hamilton RG. Clinical laboratory assessment of immediate-type hypersensitivity. J Allergy Clin Immunol 2010; 125:S284.
  3. Morgenstern JP, Griffith IJ, Brauer AW, et al. Amino acid sequence of Fel dI, the major allergen of the domestic cat: protein sequence analysis and cDNA cloning. Proc Natl Acad Sci U S A 1991; 88:9690.
  4. Weghofer M, Grote M, Resch Y, et al. Identification of Der p 23, a peritrophin-like protein, as a new major Dermatophagoides pteronyssinus allergen associated with the peritrophic matrix of mite fecal pellets. J Immunol 2013; 190:3059.
  5. Grönlund H, Saarne T, Gafvelin G, van Hage M. The major cat allergen, Fel d 1, in diagnosis and therapy. Int Arch Allergy Immunol 2010; 151:265.
  6. Ownby DR, Tomlanovich M, Sammons N, McCullough J. Anaphylaxis associated with latex allergy during barium enema examinations. AJR Am J Roentgenol 1991; 156:903.
  7. Pollen count information is available through the website of the American Academy of Allergy, Asthma, and Immunology. www.aaaai.org/nab (Accessed on August 23, 2010).
  8. Hamilton RG. Assessment of indoor allergen exposure. Curr Allergy Asthma Rep 2005; 5:394.
  9. Hamilton RG, Eggleston PA. Environmental allergen analyses. Methods 1997; 13:53.
  10. Thomas WR, Smith WA, Hales BJ. The allergenic specificities of the house dust mite. Chang Gung Med J 2004; 27:563.
  11. Leitermann K, Ohman JL Jr. Cat allergen 1: Biochemical, antigenic, and allergenic properties. J Allergy Clin Immunol 1984; 74:147.
  12. Bollinger ME, Eggleston PA, Flanagan E, Wood RA. Cat antigen in homes with and without cats may induce allergic symptoms. J Allergy Clin Immunol 1996; 97:907.
  13. de Groot H, Goei KG, van Swieten P, Aalberse RC. Affinity purification of a major and a minor allergen from dog extract: serologic activity of affinity-purified Can f I and of Can f I-depleted extract. J Allergy Clin Immunol 1991; 87:1056.
  14. Matsui EC, Simons E, Rand C, et al. Airborne mouse allergen in the homes of inner-city children with asthma. J Allergy Clin Immunol 2005; 115:358.
  15. Arbes SJ Jr, Sever M, Mehta J, et al. Abatement of cockroach allergens (Bla g 1 and Bla g 2) in low-income, urban housing: month 12 continuation results. J Allergy Clin Immunol 2004; 113:109.
  16. Perry TT, Vargas PA, Bufford J, et al. Classroom aeroallergen exposure in Arkansas head start centers. Ann Allergy Asthma Immunol 2008; 100:358.
  17. Luczynska CM, Arruda LK, Platts-Mills TA, et al. A two-site monoclonal antibody ELISA for the quantification of the major Dermatophagoides spp. allergens, Der p I and Der f I. J Immunol Methods 1989; 118:227.
  18. Earle CD, King EM, Tsay A, et al. High-throughput fluorescent multiplex array for indoor allergen exposure assessment. J Allergy Clin Immunol 2007; 119:428.
  19. Pate AD, Hamilton RG, Ashley PJ, et al. Proficiency testing of allergen measurements in residential dust. J Allergy Clin Immunol 2005; 116:844.
  20. Platts-Mills TA, Ward GW Jr, Sporik R, et al. Epidemiology of the relationship between exposure to indoor allergens and asthma. Int Arch Allergy Appl Immunol 1991; 94:339.
  21. Platts-Mills TA, Chapman MD, Pollart SM, et al. Establishing health standards for indoor foreign proteins related to asthma: dust mite, cat and cockroach. Toxicol Ind Health 1990; 6:197.
  22. Sheehan WJ, Rangsithienchai PA, Wood RA, et al. Pest and allergen exposure and abatement in inner-city asthma: a work group report of the American Academy of Allergy, Asthma & Immunology Indoor Allergy/Air Pollution Committee. J Allergy Clin Immunol 2010; 125:575.