Transitioning to Extensively Hydrolyzed Formula (eHF) for Suspected Cow's Milk Protein Allergy
Direct Transition Approach
For an 11-week-old infant with suspected cow's milk protein allergy, switch immediately and completely to an extensively hydrolyzed casein formula without gradual mixing or transition periods. 1, 2
Formula Selection Strategy
First-Line Choice: Extensively Hydrolyzed Casein Formula
Extensively hydrolyzed casein formulas are the recommended first-line treatment for infants under 6 months with suspected cow's milk protein allergy presenting with mild to moderate symptoms 1, 3, 4
These formulas are tolerated by more than 90% of infants with confirmed cow's milk protein allergy, meeting international hypoallergenicity standards 5, 6
The molecular weight of peptides in these formulas is typically less than 2.5 kDa, with approximately 50% consisting of free amino acids and small peptides 7
When to Escalate to Amino Acid Formula
Switch to an elemental (amino acid-based) formula if the infant does not tolerate the extensively hydrolyzed formula within 2-4 weeks, indicated by persistent vomiting, diarrhea, blood in stools, or failure to thrive 1, 2
Amino acid formulas are the first-line choice for severe presentations including anaphylaxis, eosinophilic esophagitis, or food protein-induced enterocolitis syndrome (FPIES) 1, 4
Avoid Soy Formula at This Age
- Do not use soy formula for an 11-week-old infant as it is only recommended for infants over 6 months of age, and 20-40% of infants with cow's milk allergy also react to soy 1, 4
Monitoring Requirements
Symptom Resolution Timeline
Expect symptom improvement within 2-4 weeks of starting the extensively hydrolyzed formula 3, 5
Monitor for resolution of gastrointestinal symptoms (vomiting, diarrhea, blood in stools), skin manifestations (eczema), and irritability 3, 4
Growth Monitoring
Track weight and length at 2 weeks, 1 month, and monthly thereafter to ensure adequate catch-up growth and normalization of weight-for-age z-scores 1, 2, 5
Infants on appropriate formula should demonstrate catch-up growth within the first month 5
Red Flags Requiring Formula Change
Persistent vomiting or worsening symptoms after 2-4 weeks indicates the need to escalate to amino acid formula 1
Failure to gain weight appropriately or continued bloody stools warrants immediate reassessment 4
Common Pitfalls to Avoid
Do not gradually mix the new formula with the old cow's milk formula as this continues allergen exposure and delays symptom resolution 3
Do not empirically switch between multiple formulas without recognizing the pattern of symptoms; if extensively hydrolyzed formula fails, move directly to amino acid formula rather than trying soy or partially hydrolyzed options 1
Do not use partially hydrolyzed formulas as these are not appropriate for treatment of cow's milk protein allergy and are only marketed for prevention (which is not evidence-based) 8, 2
Highly Rated eHF Formula Brands
Note: Specific brand availability varies by location. The following are internationally recognized extensively hydrolyzed formulas:
Extensively Hydrolyzed Casein Formulas
- Nutramigen (Mead Johnson/Reckitt) - casein-based 7
- Alimentum (Abbott) - casein-based
- Pregestimil (Mead Johnson) - casein-based with MCT oil
Extensively Hydrolyzed Whey Formulas
- Products meeting hypoallergenicity standards with peptides <2.5 kDa 6
Amino Acid Formulas (if eHF not tolerated)
Bottle Teats/Nipples
Standard bottle nipples are appropriate for extensively hydrolyzed formulas as they have similar flow characteristics to standard formulas:
- Use slow-flow (0-3 months) or medium-flow (3-6 months) nipples appropriate for the infant's age
- Any major brand nipple (Philips Avent, Dr. Brown's, Tommee Tippee, MAM) is suitable
- No specialized nipples are required for eHF formulas
Vitamin Supplementation
- Continue vitamin D supplementation at 400 IU daily as recommended for all breastfed infants and those consuming less than 28 ounces of formula per day 2