From the Guidelines
The mother should be counseled that her infant will likely outgrow her milk protein intolerance. This infant's presentation with watery diarrhea and blood in the stool after consuming cow milk-based formula, which resolved when switched to soy-based formula, is consistent with cow's milk protein intolerance rather than lactose intolerance. Milk protein intolerance is common in infants and typically resolves by 3-5 years of age as the immune system matures and develops tolerance, as suggested by the 2011 guidelines for managing food allergy 1. Unlike lactose intolerance, which involves difficulty digesting milk sugar and rarely presents with bloody stools, milk protein intolerance is an immune-mediated reaction to proteins in cow's milk. The fact that the infant is growing well at the 50th percentile for all measurements indicates that the current dietary management with soy formula is appropriate. Key points to consider include:
- Most children with food allergy eventually tolerate cow’s milk, egg, soy, and wheat 1
- The presence of high initial levels of specific IgE antibodies, additional atopic disease, or allergy to more than 1 food are risk factors for persistence of food allergy 1
- A decrease in food-specific IgE levels is often a marker for the onset of tolerance 1 The mother should be advised that while her child needs to avoid cow's milk products now, reintroduction can be attempted under medical supervision after 12 months of age, with most children developing tolerance by early childhood.
From the Research
Dietary Considerations for the Patient
The patient's symptoms of watery diarrhea with blood in her stool resolved after being switched from a cow milk-based formula to a soy-based formula. Considering this, the mother should be counseled about the following:
- The patient's intolerance to cow's milk protein, which is a common condition that can cause symptoms such as diarrhea and vomiting 2
- The possibility that the patient may outgrow her milk protein intolerance, as some children with cow's milk protein intolerance can develop tolerance over time 3, 4
- The importance of monitoring the patient's symptoms and adjusting her diet accordingly, as some children may have persistent intolerance to cow's milk protein or develop intolerance to soy protein 5, 6
Potential Outcomes
The patient's condition may be managed with a soy-based formula, but it is essential to consider the following: