Intradermal skin tests in the diagnostic evaluation of food allergy
Authors: Hugh A. Sampson, James P. Rosen, Jay E. Selcow, Louis Mendelson, Marshall P. Grodofsky, Jeffrey M. Factor, S.Allan Bock, A.Wesley Burks, John M. James, Robert Zeiger, John W. Yunginger
Journal: Journal of Allergy and Clinical Immunology (1996)

To the Editor:We were somewhat dismayed to read Dr. Golden’s commentary in the September 1995 issue of the Journal advocating the use of intradermal skin tests in the diagnostic evaluation of food allergy. In part his letter addressed the study by Rosen et al. (Skin testing with natural foods in patients suspected of having food allergies: Is it a necessity? J Allergy Clin Immunol 1994;93:1068-70) and in part presented his “clinical experience.” We would like to comment on both aspects of his letter.The purpose of the brief communication by Rosen et al. was to review our experience with the use of natural foods for skin prick testing, not to review in detail alternative methods of detection of IgE antibody. Bock et al.1Bock S Buckley J Holst A May C. Proper use of skin tests with food extracts in diagnosis of food hypersensitivity.Clin Allergy. 1978; 8: 559-564Crossref PubMed Scopus (148) Google Scholar clearly demonstrated that intradermal skin tests with foods were no more diagnostic than skin prick tests and only increased the number of “clinically false-positive” results. The utility of the RAST in diagnosing food allergy has been shown to be similar to that of the skin prick test.2Sampson HA Albergo R. Comparison of results of skin tests, RAST, and double-blind, placebo-controlled food challenges in children with atopic dermatitis.J ALLERGY CLIN IMMUNOL. 1984; 74: 26-33Abstract Full Text PDF PubMed Scopus (509) Google Scholar As noted in patients with the oral allergy syndrome,3Ortolani C Ispano M Pastorello EA Ansaloni R Magri GC. Comparison of results of skin prick tests (with fresh foods and commercial food extracts) and RAST in 100 patients with oral allergy syndrome.J ALLERGY CLIN IMMUNOL. 1989; 83: 683-690Abstract Full Text PDF PubMed Scopus (386) Google Scholar commercial food extracts will, on rare occasions, lack certain relevant protein fractions to which a patient may experience systemic symptoms, probably because of the destruction of some allergenic epitopes during the production of certain food extracts. The brief report outlined a number of such cases in which patients were shown to react to the food during a controlled food challenge (or in which patients had a clear history of anaphylaxis) and had negative skin prick test responses to commercial extracts but positive skin prick test responses to fresh food. Although the intradermal skin tests performed with those same commercial extracts may be more sensitive (or irritating), they are far less specific. Use of this less specific test will certainly provide more “positive” results, but whether they have anything to do with clinical reactivity remains to be proven.Dr. Golden suggested that it is inconvenient for patients to return for skin testing with fresh foods and that a positive intradermal test result would limit the necessity for such testing. Given that intradermal skin tests would undoubtedly produce more positive responses, some patients would not have to return for further skin testing, but whether an accurate diagnosis of food allergy would be rendered is doubtful. One step we often use to limit the number of patient visits is to request that patients bring some of the food or foods in question when they set up the initial appointment. Nevertheless, the inconvenience of an extra clinic appointment is far less than the inconvenience of being inappropriately labeled “food allergic” and being required to avoid that food for years to come. In addition, such labeling of patients as food allergic can lead to malnutrition or delay of appropriate evaluation for an underlying disorder, as documented in the literature.In his letter Dr. Golden stated that “intradermal tests with foods have correlated well with food history,” citing an abstract from 1993, which has not been published in a peer-reviewed journal. It is well known that history of food reactions correlates with positive double-blind, placebo-controlled food challenge results less than 50% of the time, and even less frequently for some of the more subjective symptoms noted by Dr. Golden. The field of food allergy has moved beyond the acceptance of historical standards and other standards with such poor predictability. Before advocating the use of intradermal tests with food allergens, Dr. Golden needs to provide data demonstrating positive double-blind, placebo-controlled food challenge results in patients with negative skin prick test results and positive intradermal test results, which would refute the studies of Bock et al.1Bock S Buckley J Holst A May C. Proper use of skin tests with food extracts in diagnosis of food hypersensitivity.Clin Allergy. 1978; 8: 559-564Crossref PubMed Scopus (148) Google ScholarUntil such “clinical experience” is documented appropriately, the use of intradermal skin tests with foods must be considered “experimental.” At present, we believe that intradermal skin tests with foods are inappropriate, placing the patient at an increased risk of an adverse systemic allergic reaction with no proven increase in diagnostic benefits.1/8/74340 To the Editor:We were somewhat dismayed to read Dr. Golden’s commentary in the September 1995 issue of the Journal advocating the use of intradermal skin tests in the diagnostic evaluation of food allergy. In part his letter addressed the study by Rosen et al. (Skin testing with natural foods in patients suspected of having food allergies: Is it a necessity? J Allergy Clin Immunol 1994;93:1068-70) and in part presented his “clinical experience.” We would like to comment on both aspects of his letter.The purpose of the brief communication by Rosen et al. was to review our experience with the use of natural foods for skin prick testing, not to review in detail alternative methods of detection of IgE antibody. Bock et al.1Bock S Buckley J Holst A May C. Proper use of skin tests with food extracts in diagnosis of food hypersensitivity.Clin Allergy. 1978; 8: 559-564Crossref PubMed Scopus (148) Google Scholar clearly demonstrated that intradermal skin tests with foods were no more diagnostic than skin prick tests and only increased the number of “clinically false-positive” results. The utility of the RAST in diagnosing food allergy has been shown to be similar to that of the skin prick test.2Sampson HA Albergo R. Comparison of results of skin tests, RAST, and double-blind, placebo-controlled food challenges in children with atopic dermatitis.J ALLERGY CLIN IMMUNOL. 1984; 74: 26-33Abstract Full Text PDF PubMed Scopus (509) Google Scholar As noted in patients with the oral allergy syndrome,3Ortolani C Ispano M Pastorello EA Ansaloni R Magri GC. Comparison of results of skin prick tests (with fresh foods and commercial food extracts) and RAST in 100 patients with oral allergy syndrome.J ALLERGY CLIN IMMUNOL. 1989; 83: 683-690Abstract Full Text PDF PubMed Scopus (386) Google Scholar commercial food extracts will, on rare occasions, lack certain relevant protein fractions to which a patient may experience systemic symptoms, probably because of the destruction of some allergenic epitopes during the production of certain food extracts. The brief report outlined a number of such cases in which patients were shown to react to the food during a controlled food challenge (or in which patients had a clear history of anaphylaxis) and had negative skin prick test responses to commercial extracts but positive skin prick test responses to fresh food. Although the intradermal skin tests performed with those same commercial extracts may be more sensitive (or irritating), they are far less specific. Use of this less specific test will certainly provide more “positive” results, but whether they have anything to do with clinical reactivity remains to be proven.Dr. Golden suggested that it is inconvenient for patients to return for skin testing with fresh foods and that a positive intradermal test result would limit the necessity for such testing. Given that intradermal skin tests would undoubtedly produce more positive responses, some patients would not have to return for further skin testing, but whether an accurate diagnosis of food allergy would be rendered is doubtful. One step we often use to limit the number of patient visits is to request that patients bring some of the food or foods in question when they set up the initial appointment. Nevertheless, the inconvenience of an extra clinic appointment is far less than the inconvenience of being inappropriately labeled “food allergic” and being required to avoid that food for years to come. In addition, such labeling of patients as food allergic can lead to malnutrition or delay of appropriate evaluation for an underlying disorder, as documented in the literature.In his letter Dr. Golden stated that “intradermal tests with foods have correlated well with food history,” citing an abstract from 1993, which has not been published in a peer-reviewed journal. It is well known that history of food reactions correlates with positive double-blind, placebo-controlled food challenge results less than 50% of the time, and even less frequently for some of the more subjective symptoms noted by Dr. Golden. The field of food allergy has moved beyond the acceptance of historical standards and other standards with such poor predictability. Before advocating the use of intradermal tests with food allergens, Dr. Golden needs to provide data demonstrating positive double-blind, placebo-controlled food challenge results in patients with negative skin prick test results and positive intradermal test results, which would refute the studies of Bock et al.1Bock S Buckley J Holst A May C. Proper use of skin tests with food extracts in diagnosis of food hypersensitivity.Clin Allergy. 1978; 8: 559-564Crossref PubMed Scopus (148) Google ScholarUntil such “clinical experience” is documented appropriately, the use of intradermal skin tests with foods must be considered “experimental.” At present, we believe that intradermal skin tests with foods are inappropriate, placing the patient at an increased risk of an adverse systemic allergic reaction with no proven increase in diagnostic benefits. We were somewhat dismayed to read Dr. Golden’s commentary in the September 1995 issue of the Journal advocating the use of intradermal skin tests in the diagnostic evaluation of food allergy. In part his letter addressed the study by Rosen et al. (Skin testing with natural foods in patients suspected of having food allergies: Is it a necessity? J Allergy Clin Immunol 1994;93:1068-70) and in part presented his “clinical experience.” We would like to comment on both aspects of his letter. The purpose of the brief communication by Rosen et al. was to review our experience with the use of natural foods for skin prick testing, not to review in detail alternative methods of detection of IgE antibody. Bock et al.1Bock S Buckley J Holst A May C. Proper use of skin tests with food extracts in diagnosis of food hypersensitivity.Clin Allergy. 1978; 8: 559-564Crossref PubMed Scopus (148) Google Scholar clearly demonstrated that intradermal skin tests with foods were no more diagnostic than skin prick tests and only increased the number of “clinically false-positive” results. The utility of the RAST in diagnosing food allergy has been shown to be similar to that of the skin prick test.2Sampson HA Albergo R. Comparison of results of skin tests, RAST, and double-blind, placebo-controlled food challenges in children with atopic dermatitis.J ALLERGY CLIN IMMUNOL. 1984; 74: 26-33Abstract Full Text PDF PubMed Scopus (509) Google Scholar As noted in patients with the oral allergy syndrome,3Ortolani C Ispano M Pastorello EA Ansaloni R Magri GC. Comparison of results of skin prick tests (with fresh foods and commercial food extracts) and RAST in 100 patients with oral allergy syndrome.J ALLERGY CLIN IMMUNOL. 1989; 83: 683-690Abstract Full Text PDF PubMed Scopus (386) Google Scholar commercial food extracts will, on rare occasions, lack certain relevant protein fractions to which a patient may experience systemic symptoms, probably because of the destruction of some allergenic epitopes during the production of certain food extracts. The brief report outlined a number of such cases in which patients were shown to react to the food during a controlled food challenge (or in which patients had a clear history of anaphylaxis) and had negative skin prick test responses to commercial extracts but positive skin prick test responses to fresh food. Although the intradermal skin tests performed with those same commercial extracts may be more sensitive (or irritating), they are far less specific. Use of this less specific test will certainly provide more “positive” results, but whether they have anything to do with clinical reactivity remains to be proven. Dr. Golden suggested that it is inconvenient for patients to return for skin testing with fresh foods and that a positive intradermal test result would limit the necessity for such testing. Given that intradermal skin tests would undoubtedly produce more positive responses, some patients would not have to return for further skin testing, but whether an accurate diagnosis of food allergy would be rendered is doubtful. One step we often use to limit the number of patient visits is to request that patients bring some of the food or foods in question when they set up the initial appointment. Nevertheless, the inconvenience of an extra clinic appointment is far less than the inconvenience of being inappropriately labeled “food allergic” and being required to avoid that food for years to come. In addition, such labeling of patients as food allergic can lead to malnutrition or delay of appropriate evaluation for an underlying disorder, as documented in the literature. In his letter Dr. Golden stated that “intradermal tests with foods have correlated well with food history,” citing an abstract from 1993, which has not been published in a peer-reviewed journal. It is well known that history of food reactions correlates with positive double-blind, placebo-controlled food challenge results less than 50% of the time, and even less frequently for some of the more subjective symptoms noted by Dr. Golden. The field of food allergy has moved beyond the acceptance of historical standards and other standards with such poor predictability. Before advocating the use of intradermal tests with food allergens, Dr. Golden needs to provide data demonstrating positive double-blind, placebo-controlled food challenge results in patients with negative skin prick test results and positive intradermal test results, which would refute the studies of Bock et al.1Bock S Buckley J Holst A May C. Proper use of skin tests with food extracts in diagnosis of food hypersensitivity.Clin Allergy. 1978; 8: 559-564Crossref PubMed Scopus (148) Google Scholar Until such “clinical experience” is documented appropriately, the use of intradermal skin tests with foods must be considered “experimental.” At present, we believe that intradermal skin tests with foods are inappropriate, placing the patient at an increased risk of an adverse systemic allergic reaction with no proven increase in diagnostic benefits. 1/8/74340