Medline ® Abstracts for References 1,28,33

of 'Oral food challenges for diagnosis and management of food allergies'

1
TI
Double-blind, placebo-controlled food challenge (DBPCFC) as an office procedure: a manual.
AU
Bock SA, Sampson HA, Atkins FM, Zeiger RS, Lehrer S, Sachs M, Bush RK, Metcalfe DD
SO
J Allergy Clin Immunol. 1988;82(6):986.
 
There is now enough experience with the use of double-blind, placebo-controlled, food challenge (DBPCFC) to recommend its use as an office procedure for most patients complaining of adverse reactions to foods. This manual discusses the practical methods required for the allergist to undertake DBPCFC in the office. Thorough histories supplemented by food allergen skin testing are used to design a DBPCFC that carefully attempts to reproduce the history of food-induced symptoms described by the patient. Precautions that must be taken are delineated before challenge, as is treatment that may be required if a reaction occurs. For those foods to which challenges are positive, longitudinal evaluation with repeated challenge at appropriate intervals help to determine whether or not the problem will resolve over a period of time.
AD
National Jewish Center for Immunology and Respiratory Medicine, Denver, Colo. 80206.
PMID
28
TI
Controlled oral food challenges in children--when indicated, when superfluous?
AU
Niggemann B, Rolinck-Werninghaus C, Mehl A, Binder C, Ziegert M, Beyer K
SO
Allergy. 2005;60(7):865.
 
The diagnostic work-up of suspected food allergy includes the skin prick test (SPT), the measurement of food specific immunoglobulin E (IgE) antibodies using serologic assays, and more recently the atopy patch test (APT). For specific serum IgE and the SPT, decision points have been established for some foods allowing prediction of clinical relevance in selected cases. The APT may be helpful, especially when considered in combination with defined levels of specific IgE. Controlled oral food challenges still remain the gold standard in the diagnostic work-up of children with suspected food allergy. Most food allergic children will lose their allergy over time. As there is no laboratory parameter, which can accurately predict when clinical tolerance has been developed, controlled oral food challenges are the measure of choice. In this article, the current knowledge of predictors for the outcome of oral food challenges is reviewed and proposals for the daily practical work-up in the case of suspected food related clinical symptoms are presented.
AD
Department of Pediatric Pneumology and Immunology, University Children's Hospital Charitéof Humboldt University, Berlin, Germany.
PMID
33
TI
Positive reactions to placebo in children undergoing double-blind, placebo-controlled food challenge.
AU
Ahrens B, Niggemann B, Wahn U, Beyer K
SO
Clin Exp Allergy. 2014;44(4):572.
 
BACKGROUND: The gold standard in the diagnosis of food allergy is the double-blind, placebo-controlled oral food challenge (DBPCFC). During this challenge, patients receive the allergenic food and placebo on separate randomized days, while being monitored for clinical reactions. Interestingly, some reactions are assessed as positive although the patients had received placebo. The aim of our study was to analyze incidence and characteristics of positive placebo reactions during DBPCFCs.
METHODS: In food-allergic children, we retrospectively analyzed positive placebo reactions in DBPCFCs in 740 placebo challenges in our department. Individual characteristics were compared, such as age or IgE levels, as well as clinical symptoms.
RESULTS: Of all placebo challenges, 2.8% (21 of 740) were assessed as positive. Young children (age ≤ 1.5 years) had more (P = 0.047) positive placebo challenges (4.0%) compared to older children (age > 1.5 years; 1.5%). Children with positive placebo challenges had higher levels of total IgE (median 201 kU/L) compared to negatively classifiedchildren (median 110 kU/L). In children with positive placebo reactions, skin symptoms were observed significantly more often, with a worsening of atopic eczema (AE) as the most reported symptom.
CONCLUSION: Placebo reactions in DBPCFC are not common. Worsening of AE is the most frequent clinical reaction associated with positive placebo challenges, and young children (age ≤ 1.5 years) seem to be affected more often. Therefore - contrary to current recommendations - DBPCFC tests should be considered in infants and young children, especially those with a history of AE.
AD
Department of Pediatric Pneumology and Immunology, CharitéUniversitätsmedizin, Berlin, Germany.
PMID