A food allergy can provoke a secondary lactase deficiency due to inflammation of the intestinal mucous membrane. This event can occur in celiac disease when a secondary lactase deficiency results from atrophy of the intestinal villi; it can also occur with cases of milk protein allergies. Lactose intolerance has been observed in children with a milk protein allergy at a rate of14% versus 3% in the control group. The decrease in allergic inflammation could allow recovery of the lactase activity.