What is the most appropriate formula for an infant with confirmed cow's milk protein allergy?

Best Formula for Infant with Confirmed Cow's Milk Protein Allergy

For formula-fed infants with confirmed cow's milk protein allergy, extensively hydrolyzed formula (eHF) should be used as first-line treatment, with amino acid-based formula (AAF) reserved for severe cases, life-threatening reactions, or failure to respond to eHF within 2-4 weeks. 1

First-Line Treatment: Extensively Hydrolyzed Formula (eHF)

• eHF demonstrates 80-90% efficacy in managing cow's milk protein allergy and should be the initial formula choice for most infants with confirmed CMPA 1
• Both extensively hydrolyzed casein formulas and extensively hydrolyzed whey formulas are appropriate options, though the GINI study showed that extensively hydrolyzed casein formula (eHF-C) reduced allergy diagnoses compared to standard formula 2
• Rice-based extensively hydrolyzed formulas (eRHF) are also well-tolerated alternatives, with studies showing >90% tolerance in infants with proven CMPA and appropriate growth outcomes 3, 4

When to Use Amino Acid-Based Formula (AAF)

Switch to AAF immediately if: 1

• Symptoms are life-threatening or severe (anaphylaxis, severe enterocolitis, significant failure to thrive)
• Symptoms persist after 2-4 weeks of strict eHF treatment
• The infant has multiple food allergies or complex presentations
• There is documented reaction to eHF on oral challenge

AAF is the most hypoallergenic option available and supports healthy weight gain with improvement in allergic manifestations in infants not responding to eHF 5

Formulas to AVOID

• Partially hydrolyzed formulas are inadequate for treatment of confirmed CMPA and should never be used 1
• Soy formula is NOT recommended as first-line treatment due to 20-40% cross-reactivity risk; it may only be considered for infants >6 months after establishing tolerance by clinical challenge 1
• Goat's milk and sheep's milk are unsuitable due to high protein homology with cow's milk 1
• Standard cow's milk formula is obviously contraindicated 1

Special Considerations for Breastfed Infants

• Breastfeeding should be continued with complete maternal elimination of all cow's milk protein sources (milk, cheese, yogurt, butter, and hidden sources in processed foods) 1
• Improvement typically occurs within 72-96 hours to 1-2 weeks of strict maternal dietary elimination 1
• Maternal calcium supplementation is essential, and consultation with a registered dietitian is warranted 1
• If symptoms persist despite strict maternal elimination for 2 weeks, consultation with an allergy specialist is necessary 1

Monitoring and Follow-Up

• All children with CMPA require nutritional counseling and regular growth monitoring, as they are at higher risk for inadequate calcium and vitamin D intake 1
• Monitor weight-for-age, length-for-age, and head circumference at regular intervals 6
• Attempt reintroduction of cow's milk protein under medical supervision after 6-12 months of elimination, as most infants outgrow CMPA 7
• Perform supervised oral food challenge after 2-4 weeks of complete symptom resolution, with emergency equipment including intramuscular epinephrine available 7

Critical Pitfalls to Avoid

• Do not use partially hydrolyzed formulas for treatment of confirmed CMPA—they lack adequate protein hydrolysis 1
• Do not use soy formula as first-line treatment due to significant cross-reactivity risk 1
• Do not delay switching to AAF if the infant has failure to thrive or severe symptoms persisting despite eHF 1
• Do not discontinue breastfeeding prematurely when maternal elimination diet can effectively manage symptoms 1
• Ensure emergency preparedness with epinephrine auto-injector for IgE-mediated CMPA 7