The results of a large study published in the journal Pediatrics, has shown that childhood food allergies are more common and dangerous than previously thought. In this study, researchers conducted a detailed survey of about 38,000 families who had at least one child under the age of 18-years-old. The parents reported that 8% of the children were allergic to at least one food. Some of the earlier studies have shown the number to be around 4%.
The most common allergy was a peanut allergy, which affected about 2% of children in the study. This was followed by a milk allergy and a shellfish allergy. Tree nuts, eggs, fin fish, strawberry, wheat, and soy were the other common triggers for allergies, according to the report.
Susan Schuval, MD, pediatric allergist at Cohen Children's Medical Center in New Hyde Park, New York, commented that the study has shown that there is a very high prevalence of food allergies in the U.S. than previously recognized. Most of the allergies in children are mild, and usually fade over a period of time. However, some cases are dangerous and may be fatal.
The study reported one of the first estimates of these reactions in children. The results showed that around 40% of children have severe symptoms, like wheezing and anaphylaxis, characterized by a sudden drop in blood pressure. Researcher Ruchi S. Gupta, MD, MPH, an assistant professor of pediatrics at Northwestern University's Feinberg School of Medicine in Chicago, feels that people do not fully understand the condition and that it could be life-threatening.
According to the study, the highest levels of allergies were seen in preschoolers between the ages of 3-years-old and 5-years-old. Severe, fatal symptoms were noted more in teenage boys. Most of the fatalities are reported among teenagers and older children. When older children go out with friends to eat, they may not ask the ingredients due to potential embarrassment.
Experts, including Robert Wood, MD, director of pediatric allergic and immunology at Johns Hopkins University School of Medicine, in Baltimore, feel that the study is a very significant one, as accurate data on the prevalence of food allergies among children has been lacking. In this study, researchers were not able to use clinical data, like blood tests and medical records, as the sample size was too large. The data was based on reports from parents' and doctor’s diagnosis.
The survey, planned by a panel of experts, was conducted on a random sample of parents across the country. The symptoms of the allergic reactions were agreed upon by the experts. Researchers excluded those cases where the parent’s report of symptoms did not match the agreed reactions. Some experts feel that since clinical measures were not included in the study, the numbers reported in the study may have been skewed.
Scott H. Sicherer, MD, a professor of pediatrics at the Jaffe Food Allergy Institute at Mount Sinai Medical School in New York City, feels that the overall estimate of 8% among children is slightly towards the higher side, when compared to the reports from earlier studies. Many of the previous studies were small and had many limitations – for example, using a single question to tally allergies or using a specific trigger, like peanuts, as the focus.
The present study did not track the reports of allergies over time, therefore, one cannot say whether the study showed an increase in allergies. Sicherer feels that the study is unique because of the size and evaluation of many different foods. It also evaluated the severity and risk of allergies in children.