Volume 123, Issue 2 , Pages 417-423, February 2009
Household peanut consumption as a risk factor for the development of peanut allergy
Background
Most children with peanut allergy (PA) react on first known oral exposure to peanut. Recent data suggest cutaneous exposure as a route of sensitization.
Objectives
This study aimed to establish the relevant route of peanut exposure in the development of allergy.
Methods
Questionnaires were administered to children with PA and to high-risk controls (with egg allergy) and controls without allergy. Questionnaires were completed before subjects were aware of their PA status, avoiding recall bias. Questionnaires recorded maternal peanut consumption during pregnancy, breast-feeding, and the first year of life. Peanut consumption was determined among all household members, allowing quantification of environmental household exposure (household peanut).
Results
Median weekly household peanut in the 133 PA cases was significantly elevated (18.8 g) compared with 150 controls without allergy (6.9 g) and 160 high-risk controls (1.9 g). There were no differences in infant peanut consumption between groups. Differences in maternal peanut consumption during pregnancy (and lactation) were significant but become nonsignificant after adjusting for household peanut. A dose-response relationship was observed between environmental (nonoral) peanut exposure and the development of PA, which was strongest for peanut butter. Early oral exposure to peanut in infants with high environmental peanut exposure may have had a protective effect against the development of PA.
Conclusions
High levels of environmental exposure to peanut during infancy appear to promote sensitization, whereas low levels may be protective in atopic children. No effect of maternal peanut consumption during pregnancy or lactation is observed, supporting the hypothesis that peanut sensitization occurs as a result of environmental exposure.
Key words: Allergy, children, food allergy, peanut allergy, sensitization, peanut consumption, cutaneous exposure, environmental exposure
Abbreviations used: EA, Egg allergy, PA, Peanut allergy, SPT, Skin prick test, UK, United Kingdom
Supported by a research grant from the Food Standards Agency (United Kingdom; T07043). This grant supported the project costs, including the salary of A.T.F. over the study duration. G.L.'s salary was supported in part by the Aimwell Foundation.
Disclosure of potential conflict of interest: G. Lack has provided consultation for the advisory boards of Synovate, Novartis Xolair, and ALK-Abelló; has served as an academic lecturer for SHS Nutricia, Nestlé, and SHS International; has received research support from the Immune Tolerance Network, the National Peanut Board, the Food Standards Agency, the Medical Research Council, the Food Allergy and Anaphylaxis Network, and the Food Allergy Initiative; and has served as a scientific advisor for the Anaphylaxis Campaign and the National Peanut Board. A. T. Fox has served as a consultant for SHS Nutricia and has attended a conference for Nestlé. P. Sasieni has received research support from Cancer Research, United Kingdom. G. du Toit has received research support from the National Peanut Board, USA, and the Immune Tolerance Network, National Institutes of Health. The other author has declared that she has no conflict of interest.
PII: S0091-6749(08)02431-7
doi:10.1016/j.jaci.2008.12.014
© 2009 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.
Volume 123, Issue 2 , Pages 417-423, February 2009
