What is the management and treatment approach for an infant suspected of having Food Protein-Induced Enterocolitis Syndrome (FPIES)?

Management and Treatment of Food Protein-Induced Enterocolitis Syndrome (FPIES) in Infants

Strict dietary elimination of the trigger food is the cornerstone of FPIES management, combined with aggressive fluid resuscitation and ondansetron for acute reactions in infants ≥6 months of age. 1

Acute Episode Management

At Home

• For mild reactions (1-2 episodes of vomiting, no lethargy): Attempt oral rehydration with breast-feeding or clear fluids at home 1
• For moderate-to-severe reactions (>3 episodes of vomiting with lethargy): Call 911 or go to the emergency department immediately 1
• Critical caveat: If the child has a history of severe FPIES and definitely ingested the trigger food, call 911 even without symptoms or with any symptoms regardless of severity 1

At Medical Facility - Severity-Based Protocol

Mild (1-2 episodes of vomiting, no lethargy):

• Attempt oral rehydration (breast-feeding or clear fluids) 1
• Consider ondansetron 0.15 mg/kg IM (maximum 16 mg) if age ≥6 months 1, 2
• Monitor for resolution approximately 4-6 hours from reaction onset 1

Moderate (>3 episodes of vomiting with mild lethargy):

• Administer ondansetron 0.15 mg/kg IM (maximum 16 mg) if age ≥6 months 1, 2
• Place peripheral IV line for normal saline bolus 20 mL/kg, repeat as needed 1
• Transfer to emergency department or ICU if persistent/severe hypotension, shock, extreme lethargy, or respiratory distress develops 1

Severe (>3 episodes of vomiting with severe lethargy, hypotonia, ashen/cyanotic appearance):

• Place peripheral IV line immediately and administer normal saline bolus 20 mL/kg rapidly; repeat as needed to correct hypotension 1
• Administer IV ondansetron 0.15 mg/kg (maximum 16 mg) if age ≥6 months 1, 2
• If IV access is delayed and age ≥6 months, give ondansetron 0.15 mg/kg IM 1, 2
• Consider IV methylprednisolone 1 mg/kg (maximum 60-80 mg) 1
• Monitor and correct acid-base and electrolyte abnormalities 1
• Correct methemoglobinemia if present 1
• Discharge after 4-6 hours when patient returns to baseline and tolerates oral fluids 1

Important limitation: Ondansetron should NOT be administered to infants <6 months of age 3. Exercise special caution in children with heart disease due to QT interval prolongation risk 2.

Epinephrine is NOT routinely indicated for FPIES unless the patient has concomitant IgE-mediated allergy and is at risk for anaphylaxis 1

Long-Term Dietary Management

Formula Selection for Cow's Milk/Soy FPIES

• First-line: Extensively hydrolyzed casein-based formula 1
• If extensively hydrolyzed formula fails: 10-20% of infants require amino acid-based formula 1
• Continue breast-feeding when possible, consistent with official infant feeding recommendations 1
• Supervised introduction of soy in cow's milk FPIES (and vice versa) should be considered under physician supervision, noting 20-40% co-reactivity risk in US patients 1

Complementary Food Introduction Strategy

Strict avoidance of all forms of trigger foods (including baked and processed forms) unless already tolerated in the diet 1

Recommended progression for infants with FPIES:

• 4-6 months: Start with lower-risk vegetables (broccoli, cauliflower, parsnip, turnip, pumpkin) as smooth, thin purees 1, 4
• 6 months: Expand to fruits (blueberries, strawberries, plum, watermelon, apple, pear, orange) 1, 4
• 8 months: Introduce high-iron foods (lamb, fortified cereals, beef) as soft-cooked, bite-and-dissolve textures 1, 4
• 12 months: Offer modified family foods that are table-chopped and soft-cooked 1, 4

Critical feeding principles:

• Introduce one new food at a time and wait at least 4 days before introducing another food to observe for reactions 1, 4
• Tolerance to one food from a food group is a favorable prognostic indicator for tolerance to other foods from the same group 4
• Do NOT routinely avoid products with precautionary allergen labeling 1

Nutritional Consultation

Strongly consider nutritional consultation for ANY patient with FPIES, regardless of the number of food avoidances, to ensure adherence to dietary avoidance and adequate nutrition 1. Children with FPIES are at risk for deficiencies in energy, protein, vitamin A, vitamin D, calcium, iron, and zinc 1. Infants with ≥3 FPIES triggers are at particularly high risk for poor weight gain and food aversion 5.

Monitoring for Resolution and Food Challenges

Oral Food Challenge Protocols

• Perform food challenges in hospital or monitored setting with immediate IV resuscitation availability for children with history of severe FPIES 1
• Office-based challenges may be considered for patients with no history of severe FPIES reactions, though caution is warranted as future reaction severity cannot be predicted 1
• Success rate is high: 88% of guideline-directed oral food challenges are successful even in patients with clear history of FPIES with lethargy 6

Baked Food Introduction

• No conclusive data exists on tolerance to cow's milk and egg proteins in baked products in FPIES 1
• Small case series suggest some children tolerate baked cow's milk and egg 1
• Introduction of baked forms must be done under physician supervision 1

Common Pitfalls to Avoid

• Do not delay complementary food introduction beyond 6 months, as this increases risk of nutritional deficiencies, growth deficits, and feeding problems 1, 4
• Do not prescribe epinephrine autoinjectors routinely for FPIES alone 1
• Do not use ondansetron in infants <6 months 3
• Do not assume single-food elimination is nutritionally benign—even one food elimination can cause significant nutritional deficiency 1
• Do not perform home food challenges for suspected FPIES triggers without prior physician guidance, especially in severe cases 1