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

Component testing for animal-derived food allergies

Julie Wang, MD
Section Editor
Scott H Sicherer, MD, FAAAAI
Deputy Editor
Elizabeth TePas, MD, MS


Advances in the identification of clinically relevant allergens and the development of recombinant proteins allow for assessment of immunoglobulin E (IgE) binding to individual proteins within an allergenic food. This type of testing is known as component-resolved diagnosis (CRD). Increased sensitivity and specificity can be achieved by assessing IgE binding to separate proteins, either purified native or recombinant, thereby providing improved diagnostic accuracy in terms of predicting clinical reactivity. CRD may also provide additional prognostic information regarding the severity or persistence of food allergies.

CRD is available for plant-derived and animal-derived foods. While CRD has shown to be informative for pollen-related food allergies, the usefulness of CRD for animal-derived food allergens is not as well defined.

CRD testing for animal-derived food allergies is reviewed here. Component testing for pollen-related, plant-derived food allergies is discussed separately, including an overview of CRD and the types of assays available. An overview of testing for food allergies is also presented separately. (See "Component testing for pollen-related, plant-derived food allergies" and "Diagnostic evaluation of food allergy".)


For milk and egg allergies, component-resolved diagnosis (CRD) allows identification of immunoglobulin E (IgE) binding to specific proteins, which may be informative to distinguish between different phenotypes of milk and egg allergy. For shrimp allergy, cross-reactive proteins with other arthropods (dust mite and cockroach) can result in positive tests that may not be clinically relevant, similar to what is seen in pollen-related, plant-derived food allergies. However, no single test result taken in isolation is reliable enough to negate the need for oral food challenges. Further studies are needed to determine the utility of IgE testing to individual proteins for these foods. (See "Component testing for pollen-related, plant-derived food allergies".)

Milk — Casein (Bos domesticus [Bos d] 8) is the major allergen present in milk, accounting for 75 to 80 percent of all cow's milk proteins [1]. Beta-lactoglobulin (Bos d 5) forms a large portion of whey, accounting for approximately 10 percent of proteins in milk. Alpha-lactalbumin (Bos d 4) represents 25 percent of the whey fraction and comprises 5 percent of cow's milk proteins. Sensitization to other minor components that can be measured include serum albumin (Bos d 6) and transferrin (Bos d lactoferrin).

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: Nov 2017. | This topic last updated: Aug 01, 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. Wal JM. Bovine milk allergenicity. Ann Allergy Asthma Immunol 2004; 93:S2.
  2. Järvinen KM, Beyer K, Vila L, et al. B-cell epitopes as a screening instrument for persistent cow's milk allergy. J Allergy Clin Immunol 2002; 110:293.
  3. Ito K, Futamura M, Movérare R, et al. The usefulness of casein-specific IgE and IgG4 antibodies in cow's milk allergic children. Clin Mol Allergy 2012; 10:1.
  4. Cingolani A, Di Pillo S, Cerasa M, et al. Usefulness of nBos d 4, 5 and nBos d 8 Specific IgE Antibodies in Cow's Milk Allergic Children. Allergy Asthma Immunol Res 2014; 6:121.
  5. D'Urbano LE, Pellegrino K, Artesani MC, et al. Performance of a component-based allergen-microarray in the diagnosis of cow's milk and hen's egg allergy. Clin Exp Allergy 2010; 40:1561.
  6. Ott H, Baron JM, Heise R, et al. Clinical usefulness of microarray-based IgE detection in children with suspected food allergy. Allergy 2008; 63:1521.
  7. Nowak-Wegrzyn A, Bloom KA, Sicherer SH, et al. Tolerance to extensively heated milk in children with cow's milk allergy. J Allergy Clin Immunol 2008; 122:342.
  8. Caubet JC, Nowak-Węgrzyn A, Moshier E, et al. Utility of casein-specific IgE levels in predicting reactivity to baked milk. J Allergy Clin Immunol 2013; 131:222.
  9. Bartnikas LM, Sheehan WJ, Hoffman EB, et al. Predicting food challenge outcomes for baked milk: role of specific IgE and skin prick testing. Ann Allergy Asthma Immunol 2012; 109:309.
  10. Holen E, Elsayed S. Characterization of four major allergens of hen egg-white by IEF/SDS-PAGE combined with electrophoretic transfer and IgE-immunoautoradiography. Int Arch Allergy Appl Immunol 1990; 91:136.
  11. Lemon-Mulé H, Sampson HA, Sicherer SH, et al. Immunologic changes in children with egg allergy ingesting extensively heated egg. J Allergy Clin Immunol 2008; 122:977.
  12. Alessandri C, Zennaro D, Scala E, et al. Ovomucoid (Gal d 1) specific IgE detected by microarray system predict tolerability to boiled hen's egg and an increased risk to progress to multiple environmental allergen sensitisation. Clin Exp Allergy 2012; 42:441.
  13. Ando H, Movérare R, Kondo Y, et al. Utility of ovomucoid-specific IgE concentrations in predicting symptomatic egg allergy. J Allergy Clin Immunol 2008; 122:583.
  14. Caubet JC, Bencharitiwong R, Moshier E, et al. Significance of ovomucoid- and ovalbumin-specific IgE/IgG(4) ratios in egg allergy. J Allergy Clin Immunol 2012; 129:739.
  15. Bartnikas LM, Sheehan WJ, Larabee KS, et al. Ovomucoid is not superior to egg white testing in predicting tolerance to baked egg. J Allergy Clin Immunol Pract 2013; 1:354.
  16. Reese G, Ayuso R, Lehrer SB. Tropomyosin: an invertebrate pan-allergen. Int Arch Allergy Immunol 1999; 119:247.
  17. Pascal M, Grishina G, Yang AC, et al. Molecular Diagnosis of Shrimp Allergy: Efficiency of Several Allergens to Predict Clinical Reactivity. J Allergy Clin Immunol Pract 2015; 3:521.
  18. Boquete M, Iraola V, Morales M, et al. Seafood hypersensitivity in mite sensitized individuals: is tropomyosin the only responsible allergen? Ann Allergy Asthma Immunol 2011; 106:223.
  19. Wang J, Calatroni A, Visness CM, Sampson HA. Correlation of specific IgE to shrimp with cockroach and dust mite exposure and sensitization in an inner-city population. J Allergy Clin Immunol 2011; 128:834.
  20. Fernandes J, Reshef A, Patton L, et al. Immunoglobulin E antibody reactivity to the major shrimp allergen, tropomyosin, in unexposed Orthodox Jews. Clin Exp Allergy 2003; 33:956.
  21. Yang AC, Arruda LK, Santos AB, et al. Measurement of IgE antibodies to shrimp tropomyosin is superior to skin prick testing with commercial extract and measurement of IgE to shrimp for predicting clinically relevant allergic reactions after shrimp ingestion. J Allergy Clin Immunol 2010; 125:872.
  22. Gámez C, Sánchez-García S, Ibáñez MD, et al. Tropomyosin IgE-positive results are a good predictor of shrimp allergy. Allergy 2011; 66:1375.