What is the recommended approach for weaning a child with a known or suspected cow's milk protein allergy?

Weaning a Child with Known or Suspected Cow's Milk Protein Allergy

For breastfed infants with cow's milk protein allergy, continue breastfeeding with maternal elimination of cow's milk and dairy products from the diet; when breastfeeding is not possible or when introducing formula, use extensively hydrolyzed formula (eHF) as first-line treatment. 1, 2

Breastfed Infants During Weaning

Maternal Dietary Elimination

• The mother should completely eliminate all sources of cow's milk protein including milk, cheese, yogurt, butter, and hidden sources in processed foods. 2
• Symptom improvement typically occurs within 72-96 hours to 1-2 weeks of strict maternal dietary elimination. 1, 2
• Consultation with a registered dietitian is recommended to ensure nutritional adequacy while avoiding cow's milk proteins. 2
• The mother requires calcium supplementation and nutritional counseling to maintain her own health while breastfeeding on a restricted diet. 2

When Maternal Elimination Fails

• If symptoms persist despite strict maternal dietary elimination for 2 weeks, consultation with an allergy specialist is warranted. 2
• If the mother cannot maintain the elimination diet or the infant fails to improve, transition to a hypoallergenic formula. 2

Formula Selection During Weaning

First-Line Formula Choice

• Extensively hydrolyzed formula (eHF) of cow's milk protein is the first-line treatment for formula-fed infants, with an 80-90% success rate. 1, 2, 3
• eHF should be tolerated by at least 90% of infants with documented cow's milk protein allergy. 4

Alternative Formula Options

• Amino acid-based formula (AAF) should be used for severe reactions, life-threatening symptoms, or when eHF is not tolerated. 2, 3
• Hydrolyzed rice formula (HRF) can be recommended as a first-line alternative to cow's milk-based eHF or AAF where available, as it is cow's milk protein-free and has proven hypoallergenicity. 5
• Soy formula is NOT recommended as a first-line alternative due to potential cross-reactivity affecting 20-40% of infants with cow's milk protein allergy. 1, 2
• For infants over 6 months of age, soy formula may be considered only after establishing tolerance by clinical challenge. 3, 6
• Goat's milk and sheep's milk are NOT suitable alternatives due to high protein homology with cow's milk. 2

Introduction of Complementary Foods

Timing and Approach

• Introduce complementary foods at approximately 6 months of age when developmentally ready, but not before 4 months. 7
• Start with fruits and vegetables, followed by other complementary foods such as red meats and cereals. 1
• Do not delay introduction of allergenic foods (peanut, egg, fish) beyond 4-6 months, as early introduction may prevent other food allergies. 7
• Once allergenic foods are successfully introduced, continue regular ingestion (at least once per week) to maintain tolerance. 7

Special Considerations for High-Risk Infants

• Children with cow's milk or soy-induced food protein-induced enterocolitis syndrome (FPIES) have a 30% likelihood of reacting to solid foods, most commonly rice or oat. 1
• For infants with severe eczema or early-onset atopic dermatitis, consider skin prick testing and/or oral food challenge before introducing peanut and egg. 7

Duration of Elimination Diet

Minimum Duration

• The elimination diet should be strictly followed for at least 9-12 months of age. 3
• Most infants return to their usual state of health within 3-10 days of switching to hypoallergenic formula or maternal elimination diet. 1

Reintroduction Protocol

• Reintroduction of cow's milk protein should be attempted under medical supervision, typically after 6-12 months of elimination. 1, 2
• An oral food challenge should be carried out in the hospital setting at 9-12 months of age to assess tolerance development. 3
• The timing of reintroduction varies based on severity of initial symptoms and whether the allergy is IgE-mediated (more persistent) or non-IgE-mediated. 3
• Some children will tolerate only limited daily amounts of cow's milk protein initially. 3

Common Pitfalls to Avoid

Dietary Restrictions

• Avoid unnecessarily restrictive maternal diets beyond cow's milk elimination unless other food allergies are confirmed, as this may compromise maternal nutrition and breastfeeding ability. 2
• Do not recommend routine maternal dietary elimination if the infant is thriving and asymptomatic. 1, 2

Formula Selection Errors

• Do not use partially hydrolyzed formulas for treatment of confirmed cow's milk protein allergy, as they do not meet the 90% tolerance threshold. 4
• More infants with non-IgE-mediated cow's milk allergy than IgE-mediated allergy react to eHF due to residual cow's milk protein. 5
• Do not discontinue breastfeeding prematurely when maternal elimination diet can effectively manage symptoms. 2

Complementary Food Introduction

• Do not delay introduction of complementary foods beyond 6 months of age, as there is no evidence this prevents atopic disease. 7
• Ensure ongoing regular ingestion of successfully introduced allergens to maintain tolerance. 7