What is the recommended elimination diet and nutritional management for an 18‑month‑old child with Food Protein‑Induced Enterocolitis Syndrome (FPIES)?

FPIES Elimination Diet for an 18-Month-Old

For an 18-month-old with FPIES, strictly eliminate only the confirmed trigger food(s) while actively expanding dietary variety with lower-risk foods, and immediately involve a registered dietitian to prevent nutritional deficiencies that commonly occur even with single-food elimination. 1

Core Management Principles

Strict Avoidance of Trigger Foods Only

• Eliminate only confirmed FPIES trigger foods completely from the child's diet, as threshold doses can be as low as 0.15 g of protein/kg body weight. 1
• Do not routinely avoid products with precautionary allergen labeling unless they contain the actual trigger food as an ingredient. 1
• Avoid unnecessary elimination of multiple foods—most children with FPIES react to only one food trigger, making broad dietary restrictions unwarranted and potentially harmful. 2

Understanding Cross-Reactivity Risks

At 18 months, understanding food group cross-reactivity helps prevent both unnecessary restrictions and missed reactions:

• If the child already tolerates one food from a food group, reactions to other foods in that same group are unlikely. 1
• Cross-reactivity rates are lower than commonly feared: cow's milk FPIES has <16% risk of solid food reactions, and solid food FPIES has <25% risk of cow's milk/soy reactions. 1
• Higher cross-reactivity exists within specific groups: legume FPIES shows <80% cross-reactivity with soy, and grain FPIES (rice, oats) shows ~50% cross-reactivity with other grains. 1

Age-Appropriate Food Introduction Strategy

For 12+ Months (Current Age Group)

Offer modified tolerated foods from the family table including table-chopped meats, soft cooked vegetables, grains, and fruits. 1

Lower-risk foods to prioritize:

• Tree nuts and seed butters (thinned appropriately to prevent choking) 1
• Lamb, fortified quinoa cereal, millet 1
• Vegetables: broccoli, cauliflower, parsnip, turnip, pumpkin 1
• Fruits: blueberries, strawberries, plum, watermelon, peach, avocado 1

Higher-risk foods requiring more caution:

• Peanut and other legumes (except green pea which is lower risk) 1
• Beef, fortified grains (corn, wheat, barley cereals) 1
• Squash, carrot, white potato, green beans 1
• Apples, pears, oranges 1

Food Introduction Protocol

• Introduce new foods as single ingredients, waiting at least 4 days before introducing another food to observe for delayed reactions characteristic of FPIES. 1
• Once the child tolerates a variety of early foods, subsequent introduction can be more liberal. 1
• For children with severe cow's milk and/or soy FPIES, consider supervised in-office introduction of solid foods to promote dietary variety and prevent unnecessary avoidance. 1

Critical Nutritional Management

Mandatory Dietitian Involvement

Consultation with a registered dietitian is highly recommended and should be considered essential, as children with FPIES are at significant risk for deficiencies in energy, protein, vitamin A, vitamin D, calcium, iron, and zinc. 1

• Even single-food elimination can cause significant nutritional deficiency. 1
• Children with 3 or more FPIES triggers are at particularly increased risk for poor weight gain and developing food aversion. 3
• Limited food experiences during infancy can adversely affect food intake for many years. 1

Formula Considerations (If Applicable)

If the child still receives formula and has cow's milk FPIES:

• Use extensively hydrolyzed formula (eHF) as first-line treatment, which has 80-90% success rate. 4, 5
• Use amino acid-based formula (AAF) for severe cases or if eHF is not tolerated. 1, 5
• Avoid soy formula due to 20-40% cross-reactivity risk with cow's milk FPIES. 4, 5

Common Pitfalls to Avoid

Over-Restriction Errors

• Do not implement overly restrictive diets beyond confirmed trigger foods, as this compromises nutrition without clinical benefit. 6, 5
• Avoid delaying introduction of complementary foods past 6 months of age—guidelines recommend normal timing for food introduction. 1
• Do not routinely eliminate entire food groups based on theoretical cross-reactivity without confirmed reactions. 1

Monitoring for Complications

• Watch for signs of food aversion, which occurs more frequently in children with multiple FPIES triggers. 3
• Monitor growth parameters closely, as FPIES carries risk of failure to thrive from dietary restrictions and delayed food introduction. 1
• Recognize that caregivers report high psychosocial burden, which may require additional support. 3

Supervised Food Challenges

For an 18-month-old with established FPIES, physician-supervised oral food challenges should be considered to:

• Confirm tolerance to previously avoided foods 1
• Evaluate for resolution of FPIES to trigger foods (most cases resolve by age 3-5 years) 7, 8
• Test mixtures of several solid foods to exclude severe reaction risk, followed by gradual build-up at home 1