Earlier, McDonald's also announced that the content of trans fat in a large serving of fries is higher than previously estimated.
The three lawsuits were filed by consumers after they had French fries from the fast food giant's shops and exhibited allergic symptoms.
The lawsuits were filed in Chicago, Florida and California.
The French fries triggered gastrointestinal symptoms and other allergic reactions in these individuals.
U.S. food makers are required by law to label the major food allergens such as gluten.
Food allergy is common in the U.S. Two percent of adults and five percent of children are allergic to one food or another.
The action taken by Mc Donald's is to test its fries for gluten.