Cow's milk protein allergy is defined as an immunological reaction to one or more milk proteins. A variety of symptoms can be suggestive for cow's milk protein allergy . Cow's milk protein allergy is suspected clinically in 5-15% of infants, while most estimates of prevalence of cow's milk protein allergy vary from only 2 to 5 %. Confusion regarding cow's milk protein allergy prevalence is often due to differences in study populations, study design and a lack of defined diagnostic criteria. The importance of defined diagnostic criteria needs to be emphasised. It precludes infants from an unnecessary diet and avoids delay in diagnosis, which can lead to malnutrition. The treatment of cow's milk protein allergy is the dietary elimination of cow's milk proteins. In non-breastfed infants and children less than 2 years of age, a substitute formula is mandatory as prescribed by several international scientific societies. Extensively hydrolyzed formulas are used as therapeutic formulas. An extensively hydrolysed formula is often a whey or casein based formula in which the protein has been chopped up in smaller pieces that are less allergenic. Because of high cross-reactivity (up to 80%) and nutritional inadequacy, the use of any other animal milk or soy-based formula is precluded.The infant should be maintained on an elimination diet until the child is between 9-12 months of age or at least for 6 months, whichever occurs first. In most cases, symptoms will improve substantially within 2-4 weeks if diagnosis is correct. According to consensus in literature, a therapeutic formula is a formula tolerated by at least 90% (with 95% confidence) of cow's milk protein allergy infants. The primary study outcome will be the evaluation of the hypoallergenicity of a new aminoacid based formula in children with confirmed immunoglobulin (Ig)E- mediated CMA. According to the American Academy of Pediatrics (AAP) Subcommittee on Nutrition and Allergic Diseases a hypoallergenic formula must be tested in infants and children with hypersensitivity to cow's milk proteins, with findings verified by elimination-challenge tests under double-blind, placebo-controlled conditions (DBPCFC).

Inclusion Criteria:

• Consecutive patients aged 1-36 months with diagnosis of Immunoglobulin E-mediated cow milk allergy in the last 12 weeks,
• full and stable remission of allergy symptoms
• Written informed consent form collected by the parents.

Exclusion Criteria:

• Infant aged <1 months and >36 months,
• breast fed infants,
• other food allergies,
• other allergic diseases,
• evidence of non-IgE-mediated CMA,
• history of severe anaphylactic reaction,
• 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,
• use of systemic antibiotics or anti-mycotic drugs during 4 weeks before study entry;
• investigator's uncertainty about the willingness or ability of the subject to comply with the protocol requirements;
• participation in any other studies involving investigational or marketed products concomitantly or within two weeks prior to entry into the study.