Finding the right cheese that's what gave Shannon Nowak the most trouble.
"I know, it's just grilled cheese," said the Rochester, Mich., mother whose family has moved toward a gluten-free, casein-free diet. "But we went through six or seven months without grilled cheese sandwiches or cheese in the house. You don't realize how much you'll miss it until you can't have it."
Still, like many families with diets restricted by food allergies, sensitivities or personal preference, the Nowaks found that it's getting easier to go grocery shopping these days.
Food labeling is becoming more understandable, partly because federal law now mandates that the most common allergens be clearly listed.
It's good business, too.
Approximately 3 million children in the U.S., or about 4 percent, were reported to have a food allergy in 2007 -- a jump of 18 percent over the preceding decade, according to a 2009 report by the American Academy of Pediatrics.
For those with food allergies, a bite of the wrong thing -- even a touch of it on their skin -- can trigger a violent, life-threatening immune response known as anaphylaxis that swells the lips, face, tongue and throat and cuts off breathing.
Such allergies cause 300,000 trips to emergency departments and physician offices, 2,000 hospitalizations and 150 deaths each year, according to the National Institute of Allergy and Infectious Disease, or NIAID.
Even a bowl of vanilla ice cream can be scary if you're allergic to nuts.
"So they make rocky road ice cream, and they hose it [the equipment] down.
The next run is vanilla, but it could have trace amounts [of nuts] in the first few cartons," said Carol Finkelstein of Orchard Lake, Mich. Her son Ben, 9, is allergic to milk, sesame, tree nuts and latex.
"It's a game of Russian roulette," she said.
The issue sparked headlines in Florida last month when an elementary school -- trying to protect one child with a peanut allergy -- began mandating hand-washing each time students entered the classroom. It also ordered mouth-rinsing as soon as students arrived at school and after lunch. Snacks in the classroom were banned. A peanut-sniffing dog was brought on-site.
According to Finkelstein, the school went too far. After parents protested, it eased some of the rules.
But all of this underscores that the country is still trying to balance several things: educating those with allergies about how to protect themselves, training schools in proper emergency intervention during an attack and asking for understanding from others, she said.
Beyond allergies, there is a growing understanding of food sensitivities. This intolerance may not cause the violent immune response of a food allergy, but it can lead to other serious problems.
High-fructose corn syrup, a ubiquitous ingredient in processed food, sends pains into Libby Lee's abdomen that has the 12-year-old doubled over and vomiting violently.
That means certain pizzas or ice cream at a sleepover used to land her in the emergency room: "My stomach kind of feels like there's a knife in it," said the Michigan student.
Combined, as much as 15 percent of the U.S. population has a food allergy or sensitivity, said Dr. James Li, chairman of the Allergic Diseases in the Department of Internal Medicine at Rochester, Minn.-based Mayo Clinic.
Allergies affect about 12 million Americans. The body's immune response is triggered as if otherwise harmless substances, including food, are a threat. Some people produce a specific type of antibody called immunoglobulin E (IgE), which binds to food and triggers the release of chemicals such as histamine.
Eight foods cause 90 percent of food-allergic reactions: milk, eggs, peanuts, tree nuts, fish, shellfish, wheat and soy.
For more, visit www.foodallergy.org or www.niaid.nih. gov/topics/foodallergy.