Soy allergy in infants and children with IgE-associated cow's milk allergy

Objectives: To determine the prevalence of soy allergy in IgE-associated co w's milk allergy (CMA). Study design: Children <3.5 years with documented IgE-associated CMA (n = 9 3) were evaluated for soy allergy by double-blind, placebo-controlled food challenge, open challenge, or convincing previous history of an anaphylacti c reaction to soy. Children tolerant to soy at entry received soy formula a nd were followed up for 1 year. Results: Of this IgE-associated CMA cohort (ages 3 to 41 months), 14% (95% CI = 7.7%-22.7%) were determined to have soy allergy, 12 definitely at entr y and 1 possibly after 1 year of soy ingestion. The latter child experience d severe failure to thrive at enrollment and exhibited improved growth whil e receiving soy during follow-up but was diagnosed with eosinophilic esopha gitis at study completion. Improved growth (P < .05) occurred in the non-so y-allergic cohort ingesting soy formula (579 +/- 31 mL/d) during the year o f follow-up. Conclusions: Soy allergy occurs in only a small minority of young children with IgE-associated CMA. As such, soy formula may provide a safe and growth -promoting alternative for the majority of children with IgE-associated CMA shown to be soy tolerant at the time of introduction of soy formula.