The main purpose of this study was to observe the effect of amino acid formula on infants with cow's milk protein allergy; to evaluate the role of food avoidance and Open Food Challenge test in the diagnosis of infants with cow's milk protein allergy; to observe the allergic process in infants with cow's milk protein allergy and to explore the criteria for diagnosis and treatment.

This is a multi-center, prospective cohort study. This study plans to recruit 200 subjects. The suitable subject will be enrolled and there are seven visits through the 6-month study. Efficacy parameters are the positive incidence of open food challenge test, growth and development index (Weight, Height, Head circumference;), and the improvement of CMPA symptoms (such as SCORAD, gastrointestinal tract, respiratory, comfort scores).

Inclusion Criteria:

• Age: 0 to 6 months;
• Subject with cow's milk protein allergy (any clinical signs or symptoms of the skin, gastrointestinal tract, respiratory tract or comfortable tract)
• Unable to breastfeed;
• Vital signs are stable;
• Legal guardian has signed the informed consent.

Exclusion Criteria:

• Subject with congenital and hereditary metabolic diseases;
• Digestive tract obstruction;
• Subject with immunodeficiency diseases;
• Subject who is allergic to known components of amino acid formula powder;
• The investigator judges it is not suitable for the subject to participate in this study.

Cow's milk protein allergy infants in 0~6 months