OBJECTIVETo compare the growth and symptom remission of infants with cow's milk protein allergy, who were fed with an amino acid formula, an extensively hydrolyzed formula or soy formula.

METHODInfants who were diagnosed as cow's milk protein allergy and can not be breastfed were enrolled in the intervention group, and were assigned to three special formulae (amino acid formula, extensively hydrolyzed formula or soy formula ) according to the will of parents from March 2009 to March 2010 (n = 74). A non-randomized control group was made up of age-matched healthy children (n = 21). Anthropometric measurements and symptoms were evaluated after 30, 60, 90, and 180 days. The differences of physical growth and the therapeutic effects among each group were calculated by SPSS 13.0 package.

RESULTAfter 180 days follow-up, the weight for age Z score and length for weight Z score were -0.43 +/- 0.88 and -0.31 +/- 0.78 in patients fed with soy formula substitute, which were significantly lower than those of patients fed with amino acid formula (0.11 +/- 0.77, 0.20 +/- 0.69) , extensively hydrolyzed formula (0.10 +/- 0.62, 0.18 +/- 0.70) and control group (0.22 +/- 0.54, 0.22 +/- 0.64) (P<0.05). However, there were no significant differences in physical growth among patients fed with amino acid formula, extensively hydrolyzed formula and control group (P>0.05). Moreover, no significant difference was found in length for age and head circumference for age among four groups (P>0.05). All hypoallergenic formulae were much helpful in remission of the symptoms of eczema (P<0.05). However, amino acid formula and extensively hydrolyzed formula were more effective and rapid in relieving symptoms than soy formula (1 mo vs 2 mo) (P = 0.003).

CONCLUSIONBoth amino acid formula and extensively hydrolyzed formula can maintain the normal growth of infants with cow's milk protein allergy. While, the growth of patients fed with soy formula was significantly slower than that of the other three groups. All hypoallergenic formulae can be effective in relieving allergy symptoms, and amino acid formula or extensively hydrolyzed formula seems to be superior to soy formula.