Food Allergy in the Breastfed Infant

Kirsi Järvinen-Seppo, MD, PhD


May 13, 2014

What Does Food Allergy Look Like in Breastfeeding Infants?

Exposure to cow's-milk protein can produce acute symptoms (onset within minutes to 2 hours after exposure), such as urticaria, nasal congestion, vomiting, and anaphylaxis in IgE-mediated allergy, or delayed symptoms, such as bloody stools, frequent vomiting, and diarrhea.[14] Atopic dermatitis and GER are common problems in infancy, although only occasionally associated with food allergy. Chronic isolated nasal congestion, in the absence of other symptoms (eg, eczema and hives), is a very uncommon manifestation of food allergy. The case presented above included both chronic and acute manifestations of food allergy to cow's-milk protein.

Atopic dermatitis. Food allergy plays a pathogenic role in a subset of patients (primarily infants and children) with atopic dermatitis.[15,16] Atopic eczema and IgE-mediated reactions during breastfeeding are typically caused by proteins in cow's milk, egg white, or wheat. There are reports describing the disappearance of eczema in breastfed infants after cessation of breastfeeding[5] or after a maternal avoidance diet is begun in infants who are already food-sensitized (evidence of food-specific IgE by skin prick or blood testing), and the subsequent reappearance of symptoms upon reintroduction of milk to the mother's diet.[6]

Anaphylaxis. Anaphylaxis in infants is probably underdiagnosed,[17] and food-induced anaphylactic reactions have been reported in infants starting as early as the age of 1 month. Common allergens are cow's milk and egg, but any food can be a trigger. Respiratory symptoms[5,6] and anaphylaxis[18,19] have been reported even in exclusively breastfed infants owing to occult ingestion of food allergens, such as cow's milk and fish, in the mother's diet.

Anaphylaxis in infants is often missed because of an atypical presentation that includes lethargy, cyanosis, sudden cessation of activity, and hypotension, which can occur in the absence of cutaneous symptoms. In addition, some signs are nonspecific and commonly seen in healthy infants; these include reflux, loose stools, irritability, and sudden hoarseness. Furthermore, blood pressure is not commonly measured in infants presenting with these symptoms.

Therefore, the diagnosis of food-induced anaphylaxis may be missed in the absence of an established diagnosis, unless there is a strong suspicion of food allergy. Food-induced anaphylaxis could be the first and last sign of food allergy in the case of a fatal outcome.

Protein-induced allergic proctitis/proctocolitis. This condition usually presents by 6 months of age (typically between 2 and 8 weeks of age) with blood-streaked, mucous, loose stools, and occasionally loose or frequent stools in breastfed or formula-fed infants who otherwise appear well.[9] Frank diarrhea is not typical. Protein-induced allergic proctitis/proctocolitis is a common cause of rectal bleeding in otherwise healthy infants. The differential diagnosis includes anal fissures.

Cow's milk and soy have been considered the major causative foods, although other foods can play a role as well. With complete elimination of the offending protein from the infant's or mother's diet, clinical bleeding typically clears within 3 days. About 60% of infants with rectal bleeding have food protein-induced proctitis/proctocolitis, and about 60% of proctocolitis occurs in exclusively breastfed infants. Reports suggest that other etiologies, including viruses, can cause a similar presentation.[20,21] Most infants outgrow this disorder by 1 year of age.

Allergic EoE. This disorder is characterized by chronic, relapsing, eosinophilic inflammation of the esophagus. Children with allergic EoE have symptoms suggestive of GER, but are unresponsive to conventional GER therapies. Other presenting symptoms include feeding problems, vomiting, irritability, and dysphagia.[22] Older children may present with food impaction, or may have allergic eosinophilic gastroenteritis (eosinophilic gastroenteropathy of the stomach and intestines), which presents with abdominal pain, nausea, vomiting, diarrhea, or weight loss. Cow's milk is the most common trigger, and this disorder has been described in exclusively breastfed infants.

FPIES. FPIES is a potentially severe, non-IgE, cell-mediated gastrointestinal food hypersensitivity typically provoked by cow's milk or soy, and less commonly is the result of solid-food ingestion (such as rice, oat, fruits, or vegetables) in infants younger than 1 month.[23,24,25,26] FPIES typically presents with severe, repetitive, projectile vomiting within 3 hours after ingestion of an offending allergen, leading to lethargy, profound dehydration, and sometimes shock. Diarrhea may be present in some infants, usually starting 5-10 hours after food ingestion.

The acute phase can be the first manifestation of FPIES, or it can occur when the allergen is removed from the diet and then reintroduced. Chronic exposure (such as from a cow's-milk or soy-based formula) to the offending allergen may cause vomiting and diarrhea, failure to thrive, and hypoalbuminemia. FPIES to cow's milk and soy in exclusively breastfed infants is extremely rare, although it has been reported.[7,8]


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.