Apoptotic Enteropathy in a Neonate With Allergic Enterocolitis
On examination, his weight was 3.08 kg (z score −1.2), length 50 cm (z score −0.2), weight-for-length 18 percentile (z score −0.9). He was afebrile with normal vital signs. He had mild scleral icterus. His abdomen was soft, with normal bowel sounds and no hepatosplenomegaly. Anal inspection was normal, and rectal examination was notable for normal anal tone and a small amount of bloodstained stool that was guaiac positive. Laboratory studies yielded a normal complete blood count, with white blood cell count of 15,000/μL, hematocrit 42/μL, and platelets 331,000/μL. Eosinophil count was initially elevated at 15% but subsequently normalized to 4% on the second day. Coagulation parameters, chemistries, and liver enzymes were normal. Indirect bilirubin was 12.6 mg/dL, direct bilirubin 0.6 mg/dL, albumin 3.6 g/dL, and total protein 5.4 g/dL. C-reactive protein was mildly elevated at 0.63 mg/dL. Kidney ureter bladder x-ray showed a normal bowel gas pattern.
On presentation, he was switched to an amino acid–based formula for presumed milk protein allergy. Because of persistently bloody stools, and irritability, an ultrasound of the abdomen done on day 7 of life was normal, with no evidence of intussusception. A flexible sigmoidoscopy done on day 9 revealed diffuse erythema and rectal mucosal ulcerations. Biopsy showed severely active colitis with prominent epithelial apoptosis in intact crypts (Fig. 1A) with no increase in eosinophils, and immunostains for cytomegalovirus (CMV), adenovirus, and herpes simplex virus were negative.
He continued to have bloody stools, with irritability and intermittent emesis. An upper gastrointestinal endoscopy with small bowel series done on day 10 showed markedly delayed gastric transit with a narrow and irregular antrum. The duodenojejunal junction was appropriately located. The entire small bowel was irregular, featureless, and thickened. Given the findings on upper gastrointestinal, continued rectal bleeding and ill appearance, he was made nil per os. Esophagogastroduodenoscopy and repeat flexible sigmoidoscopy were performed on day 11. The stomach and duodenum appeared severely erythematous with punctate ulceration. The rectosigmoid colon was erythematous with prominent ulcers (Fig. 2). Histology was notable for marked increase in eosinophils in the lamina propria of the antrum and corpus of the stomach (Fig. 3), and focal active colitis was noted in the sigmoid with fibropurulent material next to an ulcer (Fig. 1B). Remarkably, no apoptotic bodies or eosinophils were found. Viral culture and CMV shell vial sent from tissue from colon and stomach were negative. An immunological workup revealed mildly low immunoglobulin G at 577 mg/dL (normal range 700–1200 mg/dL). Other immunoglobulin titers were normal. T- and B-cell subtypes were within normal range. Specific immunoglobulin E to milk and soy were negative.
The amino acid–based formula was resumed following the endoscopy, day 12 of life, and he improved rapidly with complete resolution of blood in stool during the next few days. He was discharged on day 15, and, on follow-up evaluation 2 weeks later, was noted to be tolerating the same infant formula, with good weight gain, and continued absence of blood, both grossly and microscopically, from the stool.