FPIES: The 'Other' Food Allergy

Anna Nowak-Wegrzyn, MD


April 03, 2013

Trigger Foods

Management consists of strict avoidance of the trigger food. Children with FPIES usually do not react to trace amounts of food. For the majority, approximately 82%, more than 30-50 mL of the offending food is necessary to induce a reaction.[4] However, it is difficult to determine the threshold dose for an individual child because of the delay from ingestion to symptom onset. Additionally, the threshold dose may get smaller with repeated episodes of FPIES. Therefore, it is important to educate families about the need to strictly avoid the trigger food. Extensively hydrolyzed casein formulas are recommended rather than soy-based formula due to frequent concomitant CM and soy FPIES. If soy-based formula is chosen, an OFC with soy is recommended prior to initiating soy-based formula. In up to 10%-15% of infants, an amino acid formula is needed.[5,6] In severe cases, temporary bowel rest and IV fluids may be necessary. Ingestion of cooked forms of foods is not recommended, based on the presumed T-cell involvement, because high temperature does not destroy sequential allergenic epitopes recognized by T cells.

FPIES is uncommon in exclusively breastfed infants, although rare cases of infants reacting to maternal breast milk have occurred. If a child is asymptomatic and thriving, maternal elimination of the food that has caused FPIES upon direct feeding is not necessary.

Introducing New Foods

No controlled studies of food introduction in FPIES are available. Thus, recommendations are empirical and based on limited existing data and the author's own experience. Any food already tolerated by an infant should not be restricted. Introducing yellow fruits and vegetables instead of cereal at 6 months of age has been suggested.[6] If tolerated, grains, legumes, and poultry can be introduced to the diet. However, due to a high rate of intolerance of multiple foods in solid-food FPIES, it may be beneficial to avoid these foods in the first year of life. Introduction of CM and soy may be attempted after 1 year of age, preferably under physician supervision, if there is no history of reactivity to these foods. Tolerance to 1 food from each high-risk group -- for example soy in the legume group, chicken in the poultry food group, or oat from the grains group -- increases the likelihood of tolerance to other foods from the same group.