Food allergy is a common chronic condition in childhood. Recent studies have suggested that the natural history of food allergy has changed during the last two decades, with an increased prevalence, severity of clinical manifestations, and risk of persistence into later ages. The increased food allergy prevalence in children has an important economic impact, with significant direct costs for the healthcare system and even larger costs for the families of food-allergic patients. In addition, children with food allergies are at increased risk to develop other allergic manifestations later in life. According to a recent study, children with a food allergy are 2 to 4 times more likely to develop other atopic manifestations such as asthma (4.0 times), atopic eczema (2.4 times), and respiratory allergies (3.6 times), compared to children without a food allergy. Cow's milk allergy is among the most common food allergy in early childhood, with an estimated prevalence of 2% to 3%. It has been previously showed that in children with cow milk allergy, an extensively hydrolysed casein formula supplemented with the probiotic Lactobacillus rhamnosus GG induced higher tolerance rates compared to extensively hydrolysed casein formula without Lactobacillus rhamnosus GG and other formulas. These findings were consistent with those of a 1-year follow-up study performed in the US that showed better outcomes using an extensively hydrolysed casein formula+Lactobacillus rhamnosus GG vs. an extensively hydrolysed casein formula or amino acid-based formula for the first-line dietary management of cow milk allergy. In addition it has been recently demonstrated that extensively hydrolysed casein formula + Lactobacillus rhamnosus GG reduces the incidence of other atopic manifestations and hastens the development of oral tolerance in children with IgE-mediated cow milk allergy.

The present randomized controlled trial (RCT) was designed to test whether different dietary interventions could influence the occurrence of other atopic manifestations in children with IgE-mediated cow milk allergy.

Inclusion Criteria:

• age 1-12 months
• IgE-mediated CMA

Exclusion Criteria:

• cow's milk protein-induced anaphylaxis,
• food protein induced enterocolitis syndrome,
• other food allergies,
• other allergic diseases,
• non-CMA-related atopic eczema,
• eosinophilic disorders of the gastrointestinal tract,
• chronic systemic diseases,
• congenital cardiac defects,
• active tuberculosis,
• autoimmune diseases,
• immunodeficiency,
• chronic inflammatory bowel diseases,
• celiac disease,
• cystic fibrosis,
• metabolic diseases,
• malignancy,
• chronic pulmonary diseases,
• malformations of the gastrointestinal and/or respiratory tract,
• administration of prebiotics or probiotics during the 4 weeks before enrolment.

Children who were consecutively observed at a FP office because the recent occurrence of signs and symptoms possibly related to IgE-mediated CMA were sent to our tertiary centre for paediatric allergy for possible inclusion in the study. Only subjects who met the inclusion criteria will be invited to participate to the study.Written informed consent will be obtained from the parents of each subject. Anamnestic, demographic, anthropometric and clinical data, as well as information on socio-demographic factors, family and living conditions, parental history of allergic diseases, maternal smoking during pregnancy, environmental tobacco smoke exposure, number of siblings, and pet ownership were obtained from the parents and recorded in a clinical database. For children with sure diagnosis of IgE-mediated CMA during a 3-year follow-up,3 visits every 12 months will be performed. Stool samples for metagenomics and metabolomics and blood sample for epigenetics studies will be collected.