Aggressive gastrointestinal food allergy in neonates and its possible relationship to necrotizing enterocolitis

INTRODUCTION The incidence of gastrointestinal food allergy (FA) in neonates is increasing. Despite this, cases of patients with gastrointestinal FA who develop necrotizing enterocolitis (NEC) requiring laparotomy are extremely rare. PRESENTATION OF CASE We describe two cases that presented with bloody stool with a probable diagnosis of FA as eosinophils were positive in the stool at onset. Both cases failed conservative treatment. Jejunostomy and ileostomy were performed in both cases due to secondary NEC with underlying acute FA. Post-surgery, raised peripheral blood eosinophil count, presence of cow's milk-specific IgE antibody and positive allergen-specific lymphocyte stimulation test were found. Stoma closure were performed 3 and 1 months later in both cases. Postoperative recovery was uneventful. DISCUSSION A few reports have not identified risk factors for NEC secondary to FA. Thrombocytopenia and rise in C-reactive protein (CRP) levels 2days after the development of FA may be suggestive of FA with NEC. Methicillin-resistant Staphylococcus aureus (MRSA) was detected in the fecal culture of both patients at the time of the onset of NEC. The toxic antigen produced by MRSA may cause activation of milk-protein-primed T cells and exacerbate FA. CONCLUSION The decrease of platelet levels and rise in CRP may indicate the development of secondary NEC in patients with FA. Additionally, MRSA detected in the fecal culture also may be a risk factor for NEC through the activation of cellular immunity reaction pathways.