And the growing popularity of allergen advisory labeling may confuse them and their parents as to which candies are safe and which should be avoided.
"Many of the most common food allergens are found in candy," says Anne Muñoz-Furlong, founder and CEO of the Food Allergy & Anaphylaxis Network.
"For some children, just one bite of the wrong food can bring on anaphylaxis - a severe allergic reaction that can cause death."
Eight foods account for 90 percent of all food-allergic reactions in the U.S.: milk, eggs, peanuts, tree nuts, wheat, soy, fish, and shellfish.
Of these, only the last two are not likely to be found in candy.
The incidence of food allergy has doubled in the last 10 years, and scientists aren't sure why.
More than 12 million Americans - one in 25 - are caught up in this life-altering epidemic, which results in 150-200 deaths and more than 30,000 emergency room visits each year.
There is no known cure; strict avoidance is the only way to prevent a reaction.
To make matters even trickier for those dealing with food allergy, an increasing number of food manufacturers are labeling their products with advisory warnings about the possible unintentional presence of common allergens.
Because these warnings have become so common, consumers have begun to ignore them in the belief that they're not serious, which puts them at increased risk for a reaction.
A study reported earlier this year in the Journal of Allergy and Clinical
Immunology found that fewer parents are heeding the warnings today than did several years ago.
Advisory labeling typically includes such statements as "may contain (allergen)," "manufactured on shared equipment with (allergen)," and "manufactured in the same facility with (allergen)."
Parents are urged not to ignore these warnings on Halloween treats.
As a non-candy alternative to raise money for food allergy research and education, FAAN has organized its fifth annual Trick or Treat for Food Allergy campaign for this Halloween.
Participants of all ages will collect coins instead of candy in specially marked collection boxes.
The campaign is sponsored by Abbott, makers of EleCare® and other specialty nutrition products for children. For more information, contact FAAN at (800) 929-4040 or visit www.foodallergy.org on the Web.