Allergic? I Used To Be

Children outgrow certain food allergies more than others

(RxWiki News) Families with allergic children know the routine when it comes to the foods their child has reactions to: avoid, avoid, avoid. New research suggests this doesn’t always have to be the case.

A study recently presented at the American College of Allergy, Asthma and Immunology Annual Scientific Meeting showed that many children outgrow egg and milk allergies.

These researchers found boys were significantly more likely to overcome food allergies than girls. Also, children with a history of severe food allergies were much less likely to outgrow them than food-allergic children with only mild or moderate reactions.

"Ask an allergist about food allergies."

Ruchi Gupta, MD, MPH, a pediatrician at the Northwestern University and Children’s Memorial Hospital, led the study to find out which types of food allergies children often outgrow and at what age.

The researchers asked a wide range of families with children all over the US to fill out a survey via the internet between June 2009 and February 2010. Information about 40,104 children was collected.

The survey asked questions about children who were over ten years old. The questions collected information about their lifetime experiences with the eight most common foods that trigger allergic reactions.

Families were asked about how often the child ate the foods, how old they were when they had their first experience with it and if they had a bad reaction or not. Among the children who'd had allergic reactions to food, researchers wanted to know what type of symptoms were present.

Of all the children surveyed who were over ten years old, 2,120 reported a history of food allergies. Twenty-eight percent of these children were able to eat foods they had previously had allergic reactions to.

Forty-five percent of the children with a history of milk allergies had stopped having reactions to milk. Fifty-five percent of the children with egg allergies were able to eat them when they got older. Other food allergies weren’t as frequently outgrown.

Only 16 percent of the children with tree nut allergies were able to eat them without reaction eventually, while only 14 percent of shellfish-allergic children stopped having reactions.

The average age for growing out of egg or soy allergies was seven years old. For milk allergies, kids were six years old before they stopped having reactions. The average age children outgrew their allergies was older for other types of food.

Children who overcame shellfish allergies tended to be around 11 and half years old. For those that could start to eat tree nuts and fin fish, the average age was between nine and ten.

The average age for growing out of peanut allergies was eight and a half years old. The researchers also found that severe allergic reactions like angioedema, or dangerous swelling, trouble breathing, and anaphylaxis happened much less often in children who had outgrown their food allergies.

More moderate skin reactions like eczema were more common among children who had outgrown food allergies.

“Food tolerance was observed in one in four children, with 55 percent outgrowing their egg allergy by age seven,” said Dr. Gupta.

“Developing an egg tolerance is the most common for children, followed by milk. A small proportion outgrew shellfish and tree nut allergies,” she said.

The results of this study are promising for families with food-allergic children but doctors still urge caution when experimenting with allergenic foods.

“Introducing an allergen back into a child’s diet can have severe consequences, and only should be done under the care of a board-certified allergist,” said Richard Weber, MD, the American College of Allergy, Asthma and Immunology president-elect.

The authors report no conflicts of interest. Research presented at academic conferences should be considered preliminary until published in a peer reviewed journal. The research was funded by the Institutional Development Fund at The Children's Hospital of Philadelphia.

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November 19, 2012