A prospective randomised study included 170 infants of the average age of 7 months (2 – 11 months) with milk allergy, confirmed with a double-blind, placebo-controlled challenge. Half of the infants (n = 80) were assigned to receive a soya formula (Soija-Tutteli by Valio). If it was suspected that the formula was not tolerated, a double-blind, placebo-controlled challenge was performed. Ten per cent of the children developed allergic symptoms. Moreover, the suitability of the soya formula remained uncertain in 18 % of the cases (delayed, mild symptoms). A repeated double-blind, placebo-controlled challenge would have been needed to ascertain the matter. Soya was not tolerated in 5 of 20 cases in the age group less than 6 months, whereas of the infants aged 6 – 12 months only 3 of 60 reacted to soya (p = 0.01). However, the under 6 month cohort was small; only 20 infants. Of the children receiving soya-based formula, 58 % were confirmed to have IgE antibodies to cow’s milk. Adverse reactions to soya were similar in IgE-associated and non-IgE-associated cow's milk allergy (p = 0.25). The study cohort did not include patients with enterocolitis or other enteropathy.
A randomised, multicentre study evaluated the tolerability of soya-based infant formula (Isomil, Abbott) in children with IgE-associated cow's milk allergy (n = 93, age 3 months – 3.5 years, 3.2 % less than 6 months, 17.2 % 6 months – 1 year) . The diagnosis of milk allergy was based either on a double-blind, placebo-controlled food challenge or repeated previous history of an anaphylactic reaction to milk. The criteria included the emergence of cow’s milk induced immediate (within 4 hours) cutaneous, respiratory or gastrointestinal symptoms. Soya allergy was confirmed with a randomised, double-blind, placebo-controlled food challenge in 14 % of the cohort. The proportion of infants less than 6 months of age was small (3.2 %). A negative skin prick test correlates well with the suitability of soya, as compared with food challenge testing.