(TIME.com) -- Two of Emily Cunningham's three children have food allergies. And protecting her kids is taking toll on the family budget. 

When she was nine months old, Cunningham's four-year-old daughter Elena ate a spoonful of yogurt and broke out in hives. Elena is allergic to eggs, tree nuts, dairy and peanuts, and even brief contact with one of the these hard-to-avoid items is all it takes to set off a potentially life-threatening immune reaction. 

Cunningham's eight-month-old son Wyatt has a bad dairy allergy too. 

In order to keep their kids safe and healthy, Emily Cunningham, a stay-at-home mother from Charlotte, North Carolina who writes the AllergenMenuMom blog, and her husband keep a completely allergy-free home, buying only food products that are free of any trace of their children's triggers. 

But that protection comes at a high price. Between breathing medications and epipens of epinephrine, a drug used to treat anaphylactic shock, the Cunninghams spend about $1,000 a month to safeguard their children from their allergies, and that's before the grocery bill. Emily estimates her family spends $80 a month just on rice milk. 

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About 4% to 6% of U.S. children under age 18 have food allergies, and the latest statistics show this percentage may be on the rise. 

Why so many kids are experiencing allergies to common food items still isn't clear, although experts suspect that some of the trend can be attributed to improved public health and sanitation efforts that may have made us too clean to build strong enough immunity to common allergens found in food and the environment. Kids not eating things like nuts and shellfish at an earlier age may also contribute to the rise in food allergies. 
Does this challenge her?
And protecting her kids is taking toll on the family budget. 