extensively hydrolyzed casein formula containing lactobacillus rhamnosus gg reduces the occurrence of other allergic manifestations in children with cows milk allergy 3year randomized controlled trial background children with cows milk allergy cma have an increased risk of other allergic manifestations amsobjective we performed a parallelarm randomized controlled trial to test whether administration of an extensively hydrolyzed casein formula ehcf containing the probiotic lactobacillus rhamnosus gg lgg can reduce the occurrence of other ams in children with cmamethods children with igemediated cma were randomly allocated to the ehcf or ehcflgg groups and followed for 36 months the main outcome was occurrence of at least 1 am eczema urticaria asthma and rhinoconjunctivitis the secondary outcome was tolerance acquisition which was defined as the negativization of a doubleblind food challenge results at 12 24 and 36 months ams were diagnosed according to standardized criteria tolerance acquisition was evaluated every 12 monthsresults a total of 220 children 147 boys 67 with a median age of 50 months interquartile range 3080 months were randomized 110 children were placed in the ehcf group and 110 children were placed in the ehcflgg group in the complete case analysis the absolute risk difference for the occurrence of at least 1 am over 36 months was 023 95 ci 036 to 010 p 001 and the absolute risk difference for the acquisition of cows milk tolerance was 020 95 ci 005035 p 01 at 12 months 024 95 ci 008041 p 01 at 24 months and 027 95 ci 011043 p 001 at 36 months in the sensitivity analysis the effect size of the main outcome was virtually unchanged when the occurrence of ams was assigned to all 27 missing childrenconclusions ehcflgg reduces the incidence of other ams and hastens the development of oral tolerance in children with igemediated cma