For years, McDonald's has used something of a magic phrase to describe its fries: gluten-free. People with celiac disease have never had a wide array of choices when it comes to prepared or processed foods, so the notion that McDonald's fries were gluten-free was something of a godsend.

However, in voluntarily complying with new FDA labeling requirements, McDonald's quietly added “Contains wheat and milk ingredients” to the fry ingredients listing on its website several weeks ago. Those FDA labeling requirements apply to packaged foods but not restaurant offerings and, to be fair, McDonald's claims that all wheat and dairy proteins are removed from its fries. However, the problem is with the cooking oil, which has a flavoring agent derived from wheat and dairy ingredients.

McDonald's admits it always knew wheat and dairy derivatives were in the oil, but they were not the protein component. Technically speaking, the company says the product contains no allergens, but it wanted to make consumers aware the fries were derived in part from wheat and dairy sources.

That is doing little to deter lawsuits. One in Florida claims the fries caused a young girl to “become seriously ill with conditions including advanced celiac disease, an autoimmune condition, as well as epileptic seizures and stomach ulcers.” Her parents say doctors were baffled at the girl's continued illness despite a strict non-gluten diet.

Another lawsuit, a class-action suit in Los Angeles, is also in the works. No matter the potential damages, the true costs of all this will not be strictly financial.

Foodservice and retail manufacturers be warned: make absolutely sure of the accuracy of product labels and menus. This is one of those instances where you can't just say a magic word and make everything right again and, let's face it, it's going to take a superhuman effort on McDonald's part before these particular consumers ever trust the company again.