Milk protein enteropathy is an immune response to proteins in cow’s milk that causes inflammation in the small intestine, primarily affecting infants. It differs from lactose intolerance, a digestive issue with milk sugar, and from classic IgE-mediated milk allergies that cause immediate reactions like hives. The immune system incorrectly identifies milk proteins as a threat, triggering a delayed inflammatory process in the gastrointestinal tract. This condition affects an estimated 2-3% of infants under one year old.
Identifying the Condition
Symptoms are centered on the gastrointestinal system and can develop within the first week of introducing cow’s milk-based formula. Persistent diarrhea, which may contain mucus or blood, is a primary indicator. This occurs as intestinal inflammation leads to poor nutrient absorption and bleeding. Vomiting, poor appetite, and abdominal discomfort are also common.
These digestive issues can lead to systemic problems. Poor weight gain, termed “failure to thrive,” occurs because intestinal inflammation interferes with nutrient absorption. Chronic blood loss from the intestine can also result in iron-deficiency anemia. An infant with this condition may also display irritability and lethargy from discomfort and malnutrition.
The cause is a non-IgE mediated immune response, which is different from classic allergies involving IgE antibodies that trigger rapid reactions. In this condition, a delayed reaction occurs because the immune system perceives cow’s milk proteins as harmful. This prompts immune cells to gather in the intestinal lining and cause inflammation, a process that can take hours or days to manifest after ingestion.
The Diagnostic Process
Diagnosing milk protein enteropathy begins with a detailed medical history and a physical examination. The timing of symptoms in relation to feedings is an important detail. A provider may test a stool sample for microscopic blood, which indicates intestinal inflammation. Standard allergy tests like skin-prick or blood tests that measure IgE antibodies are not helpful because this condition involves a different immune pathway.
A reliable diagnostic method is an elimination diet. This involves removing the suspected protein, most commonly cow’s milk, from the infant’s diet for two to four weeks. If symptoms resolve, it strongly suggests milk protein enteropathy. For formula-fed babies, this means switching to a specialized formula, while for breastfed infants, the mother must eliminate dairy from her diet.
To confirm the diagnosis, a doctor may recommend a medically supervised oral food challenge. This involves reintroducing cow’s milk protein to see if symptoms reappear, which must be done under a doctor’s guidance. In severe or unclear cases, a pediatric gastroenterologist might perform an endoscopy and biopsy to examine the intestinal lining for inflammation and rule out other conditions.
Management and Treatment Strategies
The treatment for milk protein enteropathy is the strict avoidance of the trigger protein. Formula-fed infants require a switch from standard formula to a hypoallergenic alternative, such as an extensively hydrolyzed formula. In these formulas, milk proteins are broken down into small pieces that the immune system is unlikely to recognize.
If an infant does not improve on an extensively hydrolyzed formula, an amino acid-based formula is required. These elemental formulas contain proteins as individual amino acids, which do not trigger an immune reaction. Soy-based formulas are not a suitable alternative, as many infants who react to cow’s milk protein also react to soy protein. Goat’s and sheep’s milk are also not recommended.
Breastfeeding mothers can continue to nurse by adopting a strict elimination diet. This involves removing all dairy from her meals, and many doctors also recommend eliminating soy due to cross-reactivity. Working with a doctor or registered dietitian helps ensure both mother and baby receive adequate nutrition, particularly calcium and vitamin D.
Long-Term Outlook and Resolution
The prognosis for milk protein enteropathy is excellent, as most children outgrow it when their immune and digestive systems mature. Many infants resolve the condition by their first birthday, and an estimated 85-90% can tolerate milk protein by age three. This spontaneous resolution distinguishes it from many other food allergies.
As the child grows, a healthcare provider will recommend reintroducing milk protein to test for tolerance. This is done gradually and under medical supervision. The reintroduction may follow a “milk ladder,” starting with baked goods containing milk before moving to less-processed dairy like yogurt or cheese.
Supervised reintroduction safely gauges the child’s tolerance and avoids a reaction. The successful reincorporation of milk into the diet marks the end of the condition. Most children can expect to enjoy a normal, unrestricted diet without long-term issues from this sensitivity.