Placebo reactions in double‐blind, placebo‐controlled food challenges in children
- 6 July 2007
- Vol. 62 (8), 905-912
- https://doi.org/10.1111/j.1398-9995.2007.01430.x
Abstract
A cardinal feature of the double-blind, placebo-controlled food challenge (DBPCFC) is that placebo administration is included as a control. To date, the occurrence and diagnostic significance of placebo events have not extensively been documented. To analyse the occurrence and features of placebo events in DBPCFCs and to assess their contribution to the diagnostic accuracy of the DBPCFC in children. The study population consisted of 132 challenges in 105 sensitized children (age range 0.7-16.6 years, median 5.3 years), who underwent DBPCFCs with cow's milk, egg, peanut, hazelnut and soy. Placebo and active food challenges were performed on different days. A total number of 17 (12.9%) positive placebo events occurred, which could be classified as immediate (9/17), late-onset (8/17), objective (11/17) or subjective (6/17). Four of 74 (5.4%) positive active food challenges were revealed to be false positive by administration of a placebo challenge. This is 3% (4/132) of all challenges. When computed by a statistical model, the false positive rate was 0.129 (12.9% of all challenges). Placebo events with diverse clinical characteristics occur in DBPCFCs in a significant number of children. The diagnostic significance of the administration of a placebo challenge is first, to identify false positive diagnoses in DBPCFCs by refuting false positive tests in individual patients. Secondly, to allow for blinding of the active food challenge. Thirdly, applying a statistical model demonstrates that some positive challenges may be false positive and that the test may need to be repeated in selected cases.Keywords
This publication has 38 references indexed in Scilit:
- No effects of probiotics on atopic dermatitis in infancy: a randomized placebo‐controlled trialClinical and Experimental Allergy, 2006
- Skin prick test to egg white provides additional diagnostic utility to serum egg white–specific IgE antibody concentration in childrenJournal of Allergy and Clinical Immunology, 2006
- Utility of the ratio of food‐specific IgE/total IgE in predicting symptomatic food allergy in childrenAllergy, 2005
- Carrot allergy: Double-blinded, placebo-controlled food challenge and identification of allergensJournal of Allergy and Clinical Immunology, 2001
- Utility of food-specific IgE concentrations in predicting symptomatic food allergyJournal of Allergy and Clinical Immunology, 2001
- Statistical model for assessing the proportion of subjects with subjective sensitisations in adverse reactions to foodsAllergy, 2001
- Patterns of food hypersensitivity during sixteen years of double-blind, placebo-controlled food challengesThe Journal of Pediatrics, 1990
- Atopic dermatitis: Clinical relevance of food hypersensitivity reactionsThe Journal of Pediatrics, 1988
- Food hypersensitivity and atopic dermatitis: Evaluation of 113 patientsThe Journal of Pediatrics, 1985