Food Protein-Induced Enterocolitis Syndrome (FPIES) is a condition that causes severe vomiting and diarrhea when a trigger food is ingested. The disorder is caused by an abnormal reaction of the immune symptom to the food protein, causing inflammation in the large and small intestines (enterocolitis). Although FPIES is a type of allergy, it differs from what is commonly referred to as “food allergy” in that a different part of the immune system is causing the reaction.

Usually, the phrase “food allergy” is used to indicate the immune system has overreacted to a food by producing an antibody called immunoglobulin E (IgE). The IgE reacts with the ingested food, triggering release of chemicals that cause immediate symptoms of the gastrointestinal, cardiac, skin, and/or respiratory systems.

FPIES, on the other hand, is caused by a different, slower part of the immune system. Symptoms do not begin until 2 to 4 hours after ingestion. The usual presentation of FPIES is a healthy infant or child that develops diarrhea or vomiting 2 to 4 hours after eating. The symptoms may be severe enough to lead to dehydration. In between episodes, if the food is avoided, the child is healthy. Dramatic symptoms recur after ingestion of the food.

The most common FPIES triggers are dairy and soy. However, any food protein can be a trigger. FPIES patients may also have more than one food trigger. Because FPIES is a non-IgE reaction, the offending food will not be revealed by classic allergy testing. Rather, a very thorough history will be taken by the evaluating physician to rule out other causes. Other means of evaluating and treating FPIES include elimination diets, elemental diets, and, rarely, food challenge.

Most children will outgrow FPIES, but until that time, FPIES is a serious condition that can require emergency treatment. If you suspect that your child has FPIES, consult your doctor or call us at 309-452-0995 or 217-717-4404 to schedule an appointment.