Protein Intolerance Follow-up

Updated: Oct 20, 2017
  • Author: Agostino Nocerino, MD, PhD; Chief Editor: Carmen Cuffari, MD  more...
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The following should be considered in food protein intolerance:

  • Infants with elevated cord serum immunoglobulin E (IgE) and a positive family history of atopy are at risk for the development of atopic disease.

  • In some infants at high risk, exclusive breastfeeding with delayed introduction of solid foods until the infant is aged 6 months may delay or possibly prevent the onset of food allergy.

  • Because small amounts of food antigens ingested by the mother are excreted in breast milk, avoidance of allergenic foods by lactating mothers can be recommended; however, randomized, controlled trials of the elimination of food allergens from the diet of mothers during pregnancy and breast-feeding or from the diet during the first year of life have not shown reductions in the risk of IgE-mediated food allergies in children at age 7 years. [51] Some studies suggest that infants who are exposed to food allergens early are less likely to have food allergies. [52] Guidelines for nutritional interventions to prevent atopic disease have been established by the American Academy of Pediatrics (AAP). [53]

  • Two systematic reviews in Cochrane Database did not find any evidence to support feeding infants with hydrolyzed formula or soy protein formula for the prevention of allergy or protein intolerance. [54, 55]

  • In the early 2000s a series of international guidelines recommended late, restricted weaning, especially in high-risk infants. A position statement from the American Academy of Pediatrics (AAP) and a document from the American College of Allergy, Asthma, and Immunology recommended withholding cow’s milk until age 1 year, eggs until age 2 years, and peanuts, and tree nuts and fish until age 3 years, particularly in high risk children. [56]  
  • Numerous subsequent prospective studies have failed to demonstrate an association between early introduction of cow's milk or complementary foods and food allergy. Conversely, an increased risk of atopic dermatitis and allergic sensitization has been associated with delayed introduction of complementary foods. Tolerance to food allergens appears to be driven by regular exposure to proteins during a ‘‘critical early window’’ of development. Therefore, concern is mounting that the recommended practices of delaying the introduction of complementary foods beyond age 6 months may increase, rather than decrease, the risk of immune disorders. Current evidence suggests that the timing of this window is most likely to be allocated between age 4 months (around 17 wk) and age 7 months. [57, 58, 59]  
  • Two position papers from ESPGHAN and AAP raise questions about the benefit of delaying the introduction of solid foods that are thought to be highly allergic beyond age 4-6 months. [58, 59] Therefore, avoidance or delayed introduction of allergenic foods for the purpose of avoiding allergies is not recommended.  
  • The intestinal microflora, or microbiome, interacts with the mucosal immune system, and, in germ-free mice, does not develop a normal oral tolerance. The intestinal flora of children with atopy has been found to differ from that of controls. These observations suggest that the normal flora can play a role in the prevention of food allergies, probably due to its substantial effect on mucosal immunity. Probiotics can potentially modulate the immune response, mainly by stimulation of Th1 cytokines that can suppress Th2 responses.  
  • A potential role for probiotics can be hypothesized. Extremely encouraging data are accumulating in this area, even if conflicting results are still reported. Administration of L rhamnosus to pregnant and lactating mothers and their offspring for the first few months of life seems to be safe and was shown to be effective in preventing the development of eczema in 50% of children at high risk for food allergy throughout the first 7 years of life. 


See the list below:

  • Food-induced intolerance is most often a temporary disease. Most children can resume consumption of the offending antigen after 1-4 years of elimination diet.

  • Thirty-nine infants with proven cow’s milk protein intolerance from a cohort of 1,749 newborns from the municipality of Odense in Denmark had a good overall prognosis, with a total recovery of 56% at age 1 year, 77% at age 2 years, 87% at age 3 years, 92% at ages 5 and 10 years, and 97% at age 15 years. [7] In children younger than 10 years, 41% developed asthma, and 31% developed rhinoconjunctivitis.

  • In food-induced proctocolitis, symptoms generally clear within several days. However, complete resolution of occult bleeding may take as long as 6 weeks.

  • Infants with IgE-mediated cow’s milk proteins allergy have a higher risk for development of allergy against environmental inhalant allergens.