Keet CA, Matsui EC, Dhillon G, Lenehan P, Paterakis M, Wood RA. Ann Allergy Asthma Immunol. 2009;102(5):410–415
PURPOSE OF THE STUDY. Wheat allergy is among the most common of food allergies, affecting ∼0.4% of children, but little is known about its natural history. The purpose of this study was to determine at what age wheat allergy is outgrown and to identify clinical and laboratory predictors of tolerance development.
STUDY POPULATION. Participants were children from the Johns Hopkins pediatric allergy clinic who had a history of symptomatic reaction (presumed immunoglobulin E [IgE] mediated) to wheat and a positive wheat-specific IgE test result. Inclusion criteria were met by 103 children.
METHODS. The study was a retrospective, medical record review. Resolution of allergy was determined by the results of food-challenge testing. Kaplan-Meier survival curves were generated to depict resolution of wheat allergy.
RESULTS. The median initial wheat-specific IgE level was 24 kU/L, and the median peak wheat-specific IgE level was 73 kU/L. Rates of resolution of wheat allergy were 29% by the age of 4 years, 56% by the age of 8 years, 65% by the age of 12 years, and 70% by the age of 14 years. Higher wheat-specific IgE levels were associated with worse outcomes. A total of 63 of 103 participants underwent a food challenge during the study period. The peak wheat-specific IgE level recorded was a useful predictor of persistent allergy, although many children with even the highest levels of wheat IgE outgrew wheat allergy.
CONCLUSIONS. The median age of resolution of wheat allergy was 6.5 years in this population. However, 35% of the patients remained allergic into their teenage years.
REVIEWERS COMMENTS. Previous attempts have been made to establish wheat IgE levels that would predict clinical reactivity and prognosis. This study, in attempting to do that, included the largest population of wheat-allergic patients that has yet been described. Patients were included on the basis of a retrospective chart review and, because the inclusion criteria did not require an oral food challenge, it is possible that at the time of initial enrollment some of the patients were no longer allergic to wheat. Tolerance was appropriately determined by food challenge; however, not all patients were challenged. This might have been because a patient had a convincing reaction after an unintentional exposure to wheat, but the authors did not make that clear. In addition, some patients had ingestion reactions while trying wheat at home, which, as the authors acknowledged, raises the possibility that wheat allergy was overdiagnosed. Another limitation is that the population (in which 90% of the children included had other food allergies) might not be representative of the general population. The authors found that peak wheat-specific IgE levels were helpful in determining prognosis. However, in clinical practice, it is difficult to determine whether the peak wheat-specific IgE level for an individual patient has been reached. Because some patients with higher specific IgE levels do tolerate wheat, the authors acknowledge that wheat IgE is less helpful in predicting clinical reactivity and prognosis, compared with other foods.
- Copyright © 2009 by the American Academy of Pediatrics