METHODS: Using electronic databases such as PubMed and Igaku Chuo Zasshi (Japan’s largest peer-reviewed medical literature database), we searched from 2000 to 2017 for case reports/series of babies who (1) underwent emergency laparotomy due to NEC and (2) were diagnosed with GI allergy based on identification eosinophilia in the stool mucous and/or eosinophilia in the intestinal mucosa (>20/HPF).
RESULTS: A total of 95 babies in 33 papers were identified as having undergone emergency laparotomy due to NEC. Among them, 7 babies (7.3%) satisfied the inclusion criteria for GI allergy (2 babies with marked GI mucosal eosinophilia and 5 with eosinophilia in the stool mucous). In all 7 babies the onset of GI allergy preceded the onset of NEC. This prevalence was significantly higher than that reported for GI allergy in the general population (0.21%). NEC babies without GI allergy (gestational age: median 25.3 W (IQR: 24.1-27.0 W); birth weight: median 696 g (IQR: 590-831 g)) were significantly (p<0.0001) more premature than those with GI allergy (gestational age: median 35 W (IQR: 32-37 W); birth weight: median 1,794 g (IQR: 1,252-2,070 g)).
CONCLUSIONS: Although there is no clear direct causal relationship, NEC in non-premature babies showed significant comorbidity with GI allergy. GI allergy’s role in the pathogenesis of NEC warrants further study.