In time: misuse and overuse of amino acid formulas in cow milk allergy

Allergic proctocolitis and enterocolitis have been successfully treated with extensively hydrolyzed formulas for many years.1 In 1997, our group and de Boissieu et al.2 in Paris reported independently two series of patients with cow milk protein induced allergy that failed to respond to extensively hydrolyzed formulas, but ultimately responded therapeutically to an amino acid-based infant formula.3 These patients were subsequently challenged with an extensively hydrolyzed formula and indeed their symptoms recurred, confirming intolerance to the extensively hydrolyzed product. IgE binding epitopes have been demonstrated in both extensively hydrolyzed whey and casein and are thought to be responsible for these reactions.4,5 An amino acidbased formula was successfully utilized to treat eosinophilic esophagitis, confirming that this disorder is in fact an allergic process amenable to dietary therapy.6 The percentage of infants with cow milk protein allergy who do not tolerate an extensively hydrolyzed formula appears be low. Traditionally, the percentage is thought to be around 5%, but some have postulated that it may be on the rise.7 Despite the low incidence of intolerance to extensively hydrolyzed protein, the use of amino acid formulas has vastly exceeded the predicted usage in many countries, despite a significant increase in the cost of therapy. Commercial promotions and government