Data indicate an increase in prevalence.
If you are not impressed by these figures, ask yourself, are you recently seeing more patients with food allergy than you did 5 or 10 years ago? I contend, yes, you are.
And the literature substantiates that. For example, studies in several countries have documented increases in certain food allergies. A phone survey found that the prevalence of allergy to peanuts and tree nuts in the general U.S. population doubled between 1997 and 2002, from 0.6% to 1.2% (J. Allergy. Clin. Immunol. 2003;112:1203-7).
Similarly, it was recently reported that the overall prevalence of food or digestive allergies among U.S. children increased by 18% between 1997 and 2007 (Centers for Disease Control and Prevention, National Center for Health Statistics Data Brief, No. 10, October 2008). Moreover, the annual number of hospital discharges with any diagnosis related to food allergy in children rose by 365% between 1998 and 2006.
There are at least three plausible main reasons for this increase.
First, allergies and asthma in general have been increasing. Rates of atopic dermatitis, anaphylaxis, and eosinophilic gastrointestinal disorders are all higher than they have been in the past. Foods are strongly implicated in these diseases.
Second, the causes of food allergy are on the rise. Today, people eat more food and a greater variety, and some of these foods cross-react with others or with noningested allergens (latex, cockroach, mite, and pollen). Commercial foods now include numerous nutrient and nonnutrient allergenic ingredients. And food proteins have been increasingly incorporated into medical diagnostics and therapeutics, particularly in dermatology.
Third, contributory factors that predispose individuals to food allergy are ever more common. Fortunately, atopic individuals have high survivorship today, but this also leads to the perpetuation and spread of the predisposing genetic traits. We are living in cleaner environments, which have implications in terms of the hygiene hypothesis. There is an obesity pandemic, and leptin has been implicated in allergic sensitization. Additional contributory factors that are growing more common include cesarean deliveries and use of antacids, and possibly also use of infant multivitamins.
The evidence for a trend of increase in food allergy is compelling.
BY SAMI L. BAHNA, M.D., DR.PH.
DR. BAHNA is a professor of pediatrics and medicine, and chief of allergy and immunology at the Louisiana State University Health Science Center in Shreveport. Dr. Bahna disclosed that he has received research funding from Genentech Inc., CSL-Behring, and Pharming, and is a consultant for Schering-Plough.
|Printer friendly Cite/link Email Feedback|
|Title Annotation:||Is there a food allergy epidemic?|
|Author:||Bahna, Sami L.|
|Publication:||Internal Medicine News|
|Date:||Mar 15, 2009|
|Previous Article:||Online Care: promises and perils.|
|Next Article:||Inconsistency of diagnosis may explain it.|