DESCRIPTION
A food allergy is a disorder in which symptoms result from immunologic responses to specific food antigens. Food antigens may cause respiratory, skin or gastrointestinal symptoms. It has been reported that adverse food reactions occur in approximately 2 to 8% in infants and children and 1% in adults.
A food challenge test is a diagnostic test used to determine food allergies. During a food challenge test, an individual is given increasing doses of the food to which sensitivity is suspected, under direct supervision of a physician as potential adverse reactions may occur. A challenge is considered positive at the first apparent sign of a reaction.
The following diagnostic tests are used to determine food allergies:
Graded Oral Food Challenge Test / Open Food Challenge
With this test, the individual ingests increasing doses of the food to which sensitivity is suspected. The suspect food in this test is in its natural form and not masked or disguised so both the physician and the individual are aware the food is being consumed. There is no special preparation when performing this test, but it is prone to bias. According to the American Academy of Allergy, Asthma and Immunology, open challenges are a good option for screening when several foods are under consideration, and if the food is tolerated, nothing further is needed.
Single Blind Food Challenge Test
With this test, the individual ingests increasing doses of the food to which sensitivity is suspected. The suspect food is masked or disguised in other food or capsules. Only the individual is unaware or “blinded”, while the physician is aware of the food being consumed. This test reduces the occurrence of bias on the part of the individual. It is useful in cases where a reaction to an open food challenge has occurred in a medical setting and there is question whether the reaction may not have been physiological.
Double Blind Food Challenge Test
This test is deemed the “gold standard” in the diagnosis of food allergies. With this test, the individual ingests increasing doses of the food to which sensitivity is suspected. Both the individual and the physician are "blinded." Tested items are disguised within other food or beverage products or in a capsule in the form of dried food. Only one food item or placebo is tested per day. This is usually done at home, but in some instances of extreme suspected hypersensitivity, it may be performed in the office setting.
Provocative Tests for Food or Food Additives
Provocative tests attempt to duplicate the individual's symptoms. There are three variations of provocative testing for food allergies that can be performed. The variations, which differ in the route of administration for the test allergen, are: intracutaneous, subcutaneous or sublingual. Aside from route, each type of testing involves the same basic method. The method includes administration of the food extract, followed by observation for any of a broad variety of subjective and objective signs and symptoms that could be interpreted as the presence of a food allergy. These tests are used primarily for research.
POLICY
Food challenge testing for the diagnosis of a food allergy is considered medically necessary if the medical appropriateness criteria are met. (See Medical Appropriateness below.)
A provocative test for the diagnosis of a food allergy is considered investigational.
See also: General Policy for Allergy Testing and Treatment
MEDICAL APPROPRIATENESS
Food challenge testing for the diagnosis of a food allergy is considered medically appropriate if ALL of the following criteria are met:
The offending agent cannot be determined by skin testing
The individual has signs and symptoms or has had a history of signs and symptoms that are highly suggestive of ingestion related hypersensitivity
IMPORTANT REMINDER
We develop Medical Policies to provide guidance to Members and Providers. This Medical Policy relates only to the services or supplies described in it. The existence of a Medical Policy is not an authorization, certification, explanation of benefits or a contract for the service (or supply) that is referenced in the Medical Policy. For a determination of the benefits that a Member is entitled to receive under his or her health plan, the Member's health plan must be reviewed. If there is a conflict between the Medical Policy and a health plan, the express terms of the health plan will govern.
ADDITIONAL INFORMATION
According to the AAAAI, in preparation for an oral food challenge test, the individual should avoid the suspected foods for at least two weeks, antihistamine use should be discontinued according to its elimination half-life, and long-term asthma medications such as β-agonists should be reduced as much as possible.
SOURCES
American Academy of Allergy, Asthma & Immunology. (1981). Physician reference materials: Position statement 8. Controversial techniques. Retrieved January 7, 2002 from http://web.archive.org/web/19970510224735/http://www.aaaai.org/profinfo/publicat/position/ps08.html#Provocative%20Testing%20(Sublingual).
American Academy of Allergy, Asthma and Immunology. (2006, March). Food allergy: a practice parameter. Retrieved March 17, 2009 http://www.jcaai.readyportal.net/file_depot/0-10000000/20000-30000/27387/folder/63948/Food_Allergy_2006.pdf.
American Academy of Allergy, Asthma and Immunology. (2006, December). AAAAI work group report: allergy diagnosis in clinical practice. Retrieved March 17, 2009 from https://aaaai.org/members/academy_statements/practice_papers/allergy_diagnosis.pdf.
Complete Guide to Medicare Coverage Issues [Computer software]. (2008, November). Food allergy testing and treatment - not covered (NCD 110.11, p. 2-54). The Ingenix Complete Guide to Medicare Coverage Issues.
Complete Guide to Medicare Coverage Issues [Computer software]. (2008, November). Challenge ingestion food testing (NCD 110.12, p. 2-54). The Ingenix Complete Guide to Medicare Coverage Issues.
du Toit, G. & Fox, A.T. (2007). Oral food challenges. Current Allergy & Clinical Immunology, 20 (1), 12-15.
Hill, D. J., Hosking, C. S., & Reyes-Benito, L.V. (2001). Reducing the need for food allergen challenges in young children: A comparison of in vitro with in vivo tests. Clinical and Experimental Allergy: Journal of the British Society for Allergy and Clinical Immunology, 31 (7), 1031-1035. Retrieved January 7, 2002 from PubMed database.
Mankad, V.S., Williams, L.W., Lee, L.A, LaBelle, G.S., Anstrom, K.J. &Burks, A.W. (2008). Safety of open food challenges in the office setting. Annals of Allergy, Asthma & Immunology, 100 (5), 469-474.
Perry, T.T., Matsui, E.C., Conover-Walker, M.K. & Wood, R.A. (2004). Risk of oral food challenges. Journal of Allergy and Clinical Immunology, 114 (5), 1164-1168.
Werfel, T. (2008). Food Allergy. Journal of the German Society of Dermatology, 6 (7), 573-583.
ORIGINAL EFFECTIVE DATE: 10/12/1998
MOST RECENT REVIEW DATE: 8/8/2009
ID_BT
Policies included in the Medical Policy Manual are not intended to certify coverage availability. They are medical determinations about a particular technology, service, drug, etc. While a policy or technology may be medically necessary, it could be excluded in a member's benefit plan. Please check with the appropriate claims department to determine if the service in question is a covered service under a particular benefit plan. Use of the Medical Policy Manual is not intended to replace independent medical judgment for treatment of individuals. The content on this Web site is not intended to be a substitute for professional medical advice in any way. Always seek the advice of your physician or other qualified health care provider if you have questions regarding a medical condition or treatment.
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