Food protein-induced enterocolitis syndrome (FPIES) is a delayed food allergy that primarily affects the gastrointestinal system, causing symptoms like vomiting, and diarrhea. While it can occur in adults, FPIES is most commonly diagnosed in infancy, often when solid foods or formula are introduced. Unlike typical food allergies that trigger immediate reactions, FPIES symptoms typically begin one to four hours after consuming a trigger food.
Understanding FPIES: A Different Kind of Food Reaction
FPIES differs from classic food allergies in a crucial way. Common food allergies often involve immunoglobulin E (IgE) antibodies, leading to rapid reactions like hives, swelling, and breathing difficulties. FPIES, however, is considered a non-IgE mediated food allergy, meaning it’s triggered by different components of the immune system. This distinction impacts how the condition is diagnosed and managed.
The condition is characterized by inflammation of the stomach and intestines (enterocolitis) in response to specific food proteins. The severity of symptoms can vary significantly, ranging from mild vomiting and diarrhea to more serious complications like dehydration and, in some cases, shock.
Common Trigger Foods
While almost any food protein can potentially trigger FPIES, certain foods are more frequently implicated. These include milk, soy, eggs, grains like rice and oats, and shellfish. The specific trigger foods can also vary geographically. For example, certain grains may be more common triggers in some parts of the world than others. In older children and adults, seafood is a more common culprit.
Symptoms and Diagnosis
The hallmark symptoms of FPIES are repeated episodes of vomiting and diarrhea. These symptoms typically begin one to four hours after ingesting the offending food. In approximately 15-20% of severe cases, patients can develop hypovolemic or distributive shock, a dangerous condition caused by a significant drop in blood pressure. Chronic FPIES can also lead to failure to thrive and weight loss in infants.
Diagnosing FPIES can be challenging. There are currently no specific biomarkers to definitively confirm the diagnosis. Doctors rely on a combination of a patient’s medical history, symptom presentation, and exclusion of other potential causes, such as infectious enteritis or sepsis. Because the symptoms can mimic other conditions, accurate diagnosis is crucial for appropriate management.
Management and Treatment
The primary management strategy for FPIES is strict avoidance of the trigger food. This requires careful label reading and communication with caregivers and food preparers. For acute reactions, the focus is on maintaining hydration, often through intravenous fluids. Ondansetron, a medication to help stop vomiting, may also be prescribed in some cases.
Periodic re-evaluations with oral food challenges, conducted under medical supervision, may be considered to assess whether a child has outgrown the allergy. However, these challenges should only be performed by experienced healthcare professionals.
Prognosis and Long-Term Outlook
The long-term outlook for children with FPIES is generally favorable. Most children outgrow FPIES by the age of 3 to 4 years. However, FPIES triggered by fish tends to persist longer. Adult-onset FPIES, particularly that caused by seafood, often has lower rates of resolution over a 3-5 year period.
FPIES is estimated to affect between 0.51% and 0.9% of children in the United States, and 0.22% of adults, translating to approximately 900,000 people affected in the U.S. Alone. The condition often develops during the first year of life, as infants begin to explore solid foods or are introduced to formula.
FPIES and Other Allergic Conditions
Individuals with FPIES may also be more likely to have other atopic conditions, such as IgE-mediated food allergies, atopic dermatitis (eczema), asthma, allergic rhinitis (hay fever), and eosinophilic esophagitis. This suggests a broader predisposition to allergic responses.
Ongoing Research and Future Directions
Research into FPIES is ongoing, with a focus on better understanding the underlying immune mechanisms and identifying potential biomarkers for diagnosis. Improved diagnostic tools and a deeper understanding of the condition will lead to more effective management strategies and improved outcomes for individuals affected by FPIES.
