"I don't see it as an offense. It is honest communication," Miller said, adding that it is the patron's responsibility to be informed and vocal about their allergies and identify themselves to the restaurant staff. In turn, it is the restaurant's responsibility to say to what extent they can feed that person.
"Once you take your own needs seriously and respect them, other people respond to that," Miller said.
But this was not always the case. The restaurant industry has been slow to embrace food allergy, given how difficult it is to train staffs that have a high rate of turnover, said Anne Muñoz-Furlong, who's chief executive of the Food Allergy and Anaphylaxis Network. In addition, the process of calling food suppliers to learn what ingredients are in the foods restaurant kitchens buy can be difficult.
But Dominique Tougne, executive chef at Bistro 110 in Chicago, said he believes attitudes toward the process are changing.
"For most of the [chefs], it used to be the pain in the butt," Tougne said. "Things have changed. People really pay attention to those people."
Like chef Tsai, Tougne also has children with serious food allergies, and he pays close attention to diners with allergies at his restaurant.
Tougne launched a new series of allergen-free dinners this year targeting one category of food allergy at a time. Tougne wanted to show that classic French cuisine can be adapted and enjoyed by people who might not be able to eat unmodified French food.
"This can't be considered a trend," Tougne said. "The allergic reactions of the people are not going to go away in six months."
Dr. David Resnick, director of the Allergy and Immunology Division at New York Presbyterian Hospital, estimates that there are about 200 fatalities each year from food allergies, with the highest incidences of death among teenagers and patients of any age eating in restaurants.
And then there are the thousands of people who survive the often scary and dangerous reactions from food allergies every year.
"At the present time there is no treatment [for allergies]," Resnick said. "The only treatment is avoidance."
Many of the large, family-style chain restaurants get it. About 3 million children in the United States have food allergies, according to the allergy network.These children eat out with their families, and the restaurant industry reflects that demographic. Places like McDonald's, Outback Steakhouse, and P.F. Chang's China Bistro post their menus online, provide nutrition and allergen information, and sometimes offer limited allergen-free menus. These restaurants also may include sessions on allergies and safety in their staff training.
But as children with allergies get older, they will be going to a wider variety of restaurants. Being offered limited menu items or getting turned away because the kitchen is not careful about cross contamination with potential allergens will be unacceptable, industry observers say. These restaurants will need to have systems in place to handle food preparation for allergic customers, the allergy network's Muñoz-Furlong said.
And paying attention pays off.
"It makes good business sense," Muñoz-Furlong said. "They become your best customers because they're very loyal."
Chefs Tsai and Tongue believe their business increases as their reputation for being allergy-friendly grows.