An exclusively cow's milk-based formula-fed 2-month-old infant develops a full-body rash. What is the most appropriate next step?

An exclusively cow's milk-based formula-fed 2-month-old infant develops a full-body rash. What is the most appropriate next step?

• A. Switch to a protein hydrolysate based formula
• B. Switch to a soy protein based formula
• C. Switch to a lactose free cow's milk based formula
• D. Switch to a high MCT oil formula

Answer: (A)

When a very young infant who is solely fed cow’s milk formula develops a full-body rash, think cow’s milk protein allergy. The best next step is to switch to a formula with proteins that have been broken down into smaller pieces, i.e., a protein hydrolysate-based formula. These extensively hydrolyzed proteins are less likely to trigger an immune reaction, allowing the gut to tolerate the formula better and the rash to improve. Soy-based formulas are not ideal in this age because infants can have or develop soy protein allergies, and many clinicians avoid relying on soy for suspected cow’s milk allergy in infants under 6 months. A lactose-free cow’s milk formula still contains the same cow’s milk proteins, so it wouldn’t address the allergy. A high MCT oil formula changes fat content and absorption, not the allergenic proteins. If symptoms persist or worsen, an amino acid–based formula may be considered, but the first and most appropriate step is switching to a hydrolyzed protein formula.

When a very young infant who is solely fed cow’s milk formula develops a full-body rash, think cow’s milk protein allergy. The best next step is to switch to a formula with proteins that have been broken down into smaller pieces, i.e., a protein hydrolysate-based formula. These extensively hydrolyzed proteins are less likely to trigger an immune reaction, allowing the gut to tolerate the formula better and the rash to improve. Soy-based formulas are not ideal in this age because infants can have or develop soy protein allergies, and many clinicians avoid relying on soy for suspected cow’s milk allergy in infants under 6 months. A lactose-free cow’s milk formula still contains the same cow’s milk proteins, so it wouldn’t address the allergy. A high MCT oil formula changes fat content and absorption, not the allergenic proteins. If symptoms persist or worsen, an amino acid–based formula may be considered, but the first and most appropriate step is switching to a hydrolyzed protein formula.