LAUSR

prominent mucosal erythema and edema involving the antrum, duodenal bulb, and the second part of the duodenum. A biopsy from the antrum and the duodenum demonstrated prominent eosinophilic infiltration of the mucosa. The pathologic finding was gastritis with eosinophilic infiltration (33 eosinophils/HPF) in the antrum and duodenitis with eosinophilic infiltration (27 eosinophils/HPF) (Fig. 1e,f). Cow’s milk allergy (CMA) was strongly suspected, and an allergen-specific lymphocyte stimulation test (ALST) was performed. The lymphocyte response to kappa-casein was markedly increased (376 c.p.m.; stimulation index 1.66; cut-off index 1.1), as was lactoferrin (2,351 c.p.m.; stimulation index 10.40; cut-off index 4.0). The patient was diagnosed with EGE due to CMA. After switching to an amino acid formula (Elemental Formula, Meiji, Tokyo, Japan) by transpyloric feeding tube, hypereosinophilia disappeared within a few weeks. The nonbilious vomiting improved and weight gain proceeded satisfactorily. The transpyloric feeding tube was removed after 1 month. The patient was discharged at 2 months of age, in good health with a body weight of 3,462 g. She was doing well on follow up at 6 months with a body weight of 6,510 g. A loading test of normal formula was performed at 6 months of age and the result was negative. It remains unclear whether sensitization to cow’s milk is caused by intrauterine sensitization before birth or secondary sensitization by feeding to neonates with EGE. However, the appearance of non-bilious vomiting on the first day of life can be attributed to transplacental sensitization in our case. Although few cases of infants with EGE mimicking HPS have been reported, the possibility of EGE with GOO should be considered even in newborns with non-bilious vomiting and suspected signs of HPS by US, to initiate prompt treatment, including antigen elimination, and to avoid unnecessary laparotomy. Disclosure