The most common type of food allergy is an “immediate hypersensitivity” reaction (i.e., Type I reaction), where the symptoms usually begin within a few minutes of exposure to the offending food. These reactions are mediated by an antibody called IgE which interacts with the protein (i.e., antigen, allergen) in the food. This interaction causes a release of chemicals which are responsible for the undesirable allergic symptoms. The most common foods that cause these types of reactions are nuts and shellfish, though any food can theoretically trigger IgE.
Food Protein-Induced Enterocolitis Syndrome (FPIES), though not as common, can also cause serious and potentially life-threatening adverse effects. IgE is not involved in these reactions, because FPIES is likely to be caused by a “cell-mediated hypersensitivity” reaction (i.e., Type IV reaction), where a specific type of white blood cell called a T-lymphocyte (i.e., T-cell) is thought to play a role.
Clinically, the most distinguishing feature of FPIES is that the symptoms typically begin a few hours after the ingestion of the food. Though it can affect people at any age, it most commonly involves infants and young children.
50 to 60% of patients with FPIES have a family history of allergic disorders such as asthma, hay fever (i.e., allergic rhinitis) or eczema (i.e., atopic dermatitis) and approximately 20% have a family history of other food allergies.
Although any food can be a trigger for FPIES, the most common culprits are milk, soy, and grains. Breast milk is not known to be a trigger and most infants develop symptoms when they are first introduced to formula or solid food.
Symptoms of FPIES (may include any or all of the following):
- Recurrent vomiting
- Diarrhea (occasionally mixed with blood)
- Failure to thrive
- Poor growth
- Shock-like symptoms – low blood pressure, pale and clammy skin; shallow fast breathing, weakness, dizziness, fainting, etc.
Note: Unlike traditional IgE-mediated allergies, FPIES reactions do not manifest with itching, hives, swelling, coughing, and/or wheezing.
Diagnosis and Testing of FPIES
FPIES is occasionally mistaken for a bacterial or viral infection. Although it is a type of allergy, prick skin tests and blood tests are not helpful in the detection of this condition. The diagnosis primarily rests on a detailed history of ingestion of specific foods, nature and severity of the symptoms in conjunction with their temporal relationship with exposure, and a detailed physical examination. Rarely oral food challenges under controlled conditions and clinical supervision are necessary to confirm the diagnosis.
Atopy patch testing is being studied for its effectiveness in diagnosing FPIES, as well as predicting if the problem food is no longer a trigger. At this time, however, it is not considered a valid test to make the diagnosis.
Management of FPIES
The only option in the management of FPIES is strict avoidance of the triggering food(s). A severe reaction might necessitate emergent intravenous fluids and rarely corticosteroid agents to control inflammation in the intestines. Occasionally, children may require hospitalization if the symptoms are very severe.
Epinephrine is usually not helpful in the treatment of FPIES and is not routinely prescribed, since this condition is a non-IgE-mediated reaction.
Most children with sensitivity to milk and soy can be well managed by switching to hypoallergenic formulas, such as a casein hydrolysate or amino acid based elemental formulas. Many children sensitive to cereal grains can tolerate yellow fruits and vegetable based age-appropriate foods. New foods are usually introduced very slowly, one food at a time, for an extended period of time per food. In protracted cases, dietary advice from a certified nutritionist can be very helpful.
Prognosis of FPIES
In most instances, FPIES resolves spontaneously with time. The affected children need to be closely monitored by a board certified allergist to determine if the condition has resolved.
With proper medical care and a personalized dietary plan to ensure proper nutrition, children with FPIES usually grow and develop normally.
We Can Help You
The board certified allergy doctors at Black & Kletz Allergy will promptly answer any questions you may have regarding FPIES or any related disorders. Our allergists have been diagnosing and treating FPIES and other food allergies in the Washington, DC, Northern Virginia, and Maryland metropolitan area for more than 50 years. We have 3 convenient locations in the DC metro area with offices in Washington, DC, McLean, VA (Tysons Corner, VA), and Manassas, VA. There is on-site parking at each location and both the Washington, DC and McLean, VA offices are Metro accessible. There is a free shuttle that runs between our McLean, VA office and the Spring Hill metro station on the silver line. To schedule an appointment, please call us at any one of our 3 locations. Alternatively, you can click Request an Appointment and we will respond within 24 hours by the next business day. Black & Kletz Allergy is dedicated in providing the most up-to-date diagnostic and treatment modalities in the field of allergy, asthma, and immunology.