Cow's milk challenge increases weakly acidic reflux in children with cow's milk allergy and gastroesophageal reflux disease

Objective: To assess and compare the pattern of reflux in a selected population of infants with cow's milk (CM) allergy (CMA) and suspected gastroesophageal reflux disease (GERD) while on dietary exclusion and following challenge with CM.

Study design: Seventeen children (median age: 14 months) with a proven diagnosis of CMA and suspected GERD underwent 48-hour multichannel intraluminal impedance-pH monitoring. For the first 24 hours, the infants were kept on amino acid-based formula, and for the subsequent 24 hours, they were challenged with CM.

Results: The total reflux episodes and the number of weakly acidic episodes were higher during CM challenge compared with the amino acid-based formula period [total reflux episodes: 105 (58-127.5) vs 65 (39-87.5), P < .001; weakly acidic episodes: 53 (38.5-60.5) vs 19 (13-26.5), P < .001; median (25th-75th)]. No differences were found for either acid or weakly alkaline episodes (not significant). The number of weakly acidic episodes reaching the proximal, mid, and distal esophagus was higher during CM challenge (P < .001). No differences were found in either acid exposure time or number of long-lasting episodes (not significant).

Conclusions: In children with CMA and suspected GERD, CM exposure increases the number of weakly acidic reflux episodes. CM challenge during 48-hour multichannel intraluminal impedance-pH monitoring identifies a subgroup of patients with allergen-induced reflux, and in selected cases of children with CMA in whom GERD is suspected, its use could be considered as part of diagnostic work-up.