Debbie Quantrille wanted answers.

Her son, Duncan, 11, had a severe case of exczema that defied all efforts to treat it. Doctors told her he’d outgrow it, but something still didn’t feel right. Debbie Quantrille hit the books, then she took Duncan to a doctor who does integrative medicine where he was tested for allergies.

Duncan had a gluten intolerance. As soon as he stopped eating gluten, a protein found in grains such as wheat, barley and rye, the exczema cleared up. Debbie Quantrille also went gluten-free, and found her sinus problems, which she had suffered with for years, disappeared. It turns out her sister was also gluten intolerant. Debbie Quantrille’s husband, Brett, and daughter, Isabel, are not gluten intolerant.

The Quantrilles’ experiences are the norm, said Mary Mack-Jeansonne, president of Celiacs of Baton Rouge. The symptoms are so different from patient to patient that people are often misdiagnosed. Mack-Jeansonne’s been living gluten-free for 17 years.

“It’s a little different,” she said. “But you can do it.”

Mack-Jeansonne became gluten intolerant after a bout of encephalitis meningitis in 1985. She said even though someone may not be gluten-intolerant today, it can be triggered by a traumatic event, such as an illness or an accident. She now runs a support group that meets four times a year to talk about coping with the illness, the doctors and the diet.

“You can help people and support people, and you can tell them what doctors don’t listen and what doctors do listen,” she said.

Gail Johnson, a retired registered dietician, is in Mack-Jeansonne’s group.

“I was one of those people for 30 years that didn’t know what was wrong with me,” she said. “Here I am a dietician and have never even thought of that before.”

She was diagnosed with gluten intolerance in 2006. Her case is especially unusual because gluten intolerance is a trait associated with people of European descent. Johnson is black.

Thinking back, she recognizes gluten intolerance in other members of her family. Her father only ate whole pieces of meat or meat he ground himself. Johnson said she didn’t know at the time that it was flour, sometimes used as an extender in ground meat, that was making him sick. He just knew that only meat he prepared himself didn’t make him sick.

Johnson said switching to a gluten-free diet was an emotional process.

“The first year at my job, you know how you bring things from the house ... I walk in the room and everything has flour on it,” she recounted. “I just started crying. Food is very emotional, and you can’t share.”

Mack-Jeansonne said that, until recently, there weren’t a lot of gluten-free products readily available. She and friend Leda Bowden, who is also gluten intolerant, tested different flour mixes and foods on their own.

“We made everything from scratch,” she said. “We did pretty good.”

Mack-Jeansonne, because she was more sensitive, would test each product first to see if she got sick. But it wasn’t always easy.

“One day, Leda called me and she says, ‘Mary, I baked the hardest hockey puck you’ve ever seen. I threw it outside and the birds pecked on it and they couldn’t fly,’” Mack-Jeansonne said.

Now, she said, many products have introduced a gluten-free version. Cream of Wheat, for example, now makes a Cream of Rice. Some Chex cereals are also gluten-free, and Betty Crocker and Bisquick both offer gluten-free baking mixes.

Debbie Quantrille says when she and her son started a gluten-free diet, they went through the family’s pantry with a black Sharpie and marked unsafe foods, and learned that some foods, like spice blends, have hidden gluten.

“You have to read every label, unless you’re picking a piece of fresh fruit or a fresh vegetable,” she said. “You never know when someone’s going to decide to sprinkle some flour on there, just for giggles.”

Because of the vagaries of a gluten-free diet, not only is the Quantrilles’ pantry divided, but so are some kitchen tools, to avoid cross-contamination. They have two toasters, one for regular bread for her husband and daughter and one for gluten-free for Debbie and Duncan. All of the meals are prepared gluten-free.

Johnson, who teaches classes on family nutrition, agreed that diet affects a person’s whole family.

“The person who feeds you determines how long you’re going to live,” she said. “When you go to that supermarket and you feed those children, you are affecting five generations. It has consequences all the way down.”

Johnson uses her own family as an example. Her mother went to live with an aunt when she was a very young child. That aunt cooked for a physician and ate healthier for it. Her mother passed those eating habits down to her children. Johnson said her mother lived much longer than any other member of her immediate family, all of whom ate the higher-fat traditional Southern foods.

A different diet, such as a gluten-free or diabetic diet, Johnson said, can mark you as an outsider in the community, particularly in the South, where social events often revolve around food.

“Sometimes you do get depressed. You just get to the point when you’re worn out” worrying about your next meal and whether you’ll get sick, she said.

But, she stressed, there are ways to cope. She suggests bringing a gluten-free dish that’s enough to share with others. She also says to focus on the health benefits of a gluten-free diet. All whole fruits and vegetables are naturally gluten-free. And more and more restaurants are offering gluten-free menus. Johnson also said that you don’t have to shop at speciality stores to get the food you love.

“You can’t change DNA, that comes with life,” Johnson said. “And you do not have to spend a lot of money buying foods; just stick to the basics. You adjust to what you have for the time.”

Quantrille adapted many of the family’s recipes to be gluten-free and swears you couldn’t tell the difference.

“I was determined that, by golly, we’re going to have gumbo,” she said.

She makes a roux from a gluten-free flour blend, and also makes gluten-free brownies and oatmeal cookies her family loves. The different flours, mixes and other foods do cost more, she said, but she feels like it’s worth it.

“Some stuff is ridiculously expensive,” she said. “But you’re paying more now versus paying down the line with medical problems.”

Editor’s note: This story was corrected on March 29, 2012, to correct the name of Debbie Quantrille’s husband, Brett.