Neonatal segmental enteritis due to cow's milk allergy.

Cow's milk protein allergy (CMPA) typically presents with persistent diarrhea or dysentery, vomiting and bleeding per rectum in young infants. CMPA is reported to mimic Hirschsprung's disease and malrotation. We report, a neonate who presented with recurrent attacks of segmental enteritis due to CMPA and the last episode presented with signs of peritonitis. He improved dramatically after elimination of cow's milk from his diet. CMPA should be considered in artificially fed babies with surgical abdomen and atypical clinical signs and symptoms.

INTRODUCTION

Cow's milk protein allergy (CMPA) results from allergy to β-lactoglobulin in cow's milk. Children usually present during the weaning period with vomiting, abdominal distension, bleeding per rectum or dysentery due to allergic proctitis, proctocolitis and enterocolitis. Failure to thrive, watery diarrhea and constipation are rarer manifestations. There are isolated case reports of CMPA mimicking/co-existing with Hirschsprung's disease (HD) and malrotation in newborns.[12] We present, a neonate with CMPA who presented with features of peritonitis and recurrent segmental enteritis.

CASE REPORT

A 30-day-old boy baby was referred with abdominal distension, feculent vomiting and failure to thrive. He was born at term to a surrogate mother and weighed 3.2 kg at birth. He was started on cow's milk 6 h after birth and was discharged on the 3rd day. He was readmitted on the 7th day of life with clinical features suggestive of sepsis and probable necrotizing enterocolitis (NEC). He was managed conservatively and discharged 5 days later on infant formula and cow's milk. A few days later, he was brought back to the treating pediatrician with recurrent vomiting, abdominal distension and weight loss. Stool for reducing substances was negative. Malrotation of the gut was suspected and a barium meal was done and found to be normal. Barium enema was also normal. The C-reactive protein (CRP) was high and he was treated with intravenous antibiotics and other supportive measures. This was his third admission with clinical features of sepsis (raised CRP). Immunodeficiency was suspected and Immunoglobulin G (IgG), Immunoglobulin M (IgM) and Immunoglobulin A (IgA) were found to be normal. He was referred to our hospital to the pediatric surgery out-patient department on day 30 with gross abdominal distension and persistent vomiting. His admission weight was 2.8 kg and he was sick, wasted and dehydrated. A clinical diagnosis of HD with enterocolitis was made. He had features of acute abdomen with feculent vomiting and tenderness. X-ray of the abdomen showed dilated bowel loops. Ultrasound showed free fluid in the abdomen. Laparotomy was done. The jejunum showed features of segmental enteritis with turbid fluid and flakes in the peritoneum [Figure 1]. Colon was collapsed. Appendix was sent for frozen section biopsy to rule out total colonic aganglionosis. It was reported to be normal. Abdomen was closed after a wash. A diagnosis of segmental enteritis with peritonitis was made. The peritoneal fluid culture showed growth of Escherichia coli and Enterococcus faecalis and he was started on appropriate antibiotics. The general condition improved’, but the abdominal distension recurred when oral feeds were initiated. Parenteral nutrition was started. He was reviewed by the pediatric Gastroenterologist who suspected food allergy. A complete Immunoglobulin profile was done. IgG, IgM, and IgA were normal for age, but the IgE level was >315 IU/ml (N ≤ 1.5). CMPA was considered and the radioallergosorbent test (RAST) assay was done and was found to be strongly positive –6.82 (N ≤ 0.1).

Figure 1

Operative picture showing dilated bowel with segmental enteritis

A diagnosis of segmental enteritis with peritonitis due to cow's milk allergy was made. Baby was started on a hypoallergenic formula. 48 h later, the abdominal distension started to resolve. He was on hypoallergenic infant formula and his discharge weight was 3.1 kg. His review weight at 7 months was 6.5 kg and the serum IgE had declined to normal levels.

DISCUSSION

CMPA is being increasingly recognized in India.[3] A consensus report compiled by the Indian pediatricians states that awareness should be created about this entity among primary care physicians as this is a common cause for diarrhea.[4] Poddar et al. have shown that CMPA is as prevalent in India as in the West. In their series, the mean age at diagnosis was 17.2 ± 7.8 months (range: 3-36 months) and the mean duration of symptoms was 8.3 ± 6.2 months (range: 4 weeks to 21 months).[3]

Children with CMPA present with the persistent diarrhea or dysentery. Lactose intolerance, failure to thrive, persistent vomiting and abdominal pain are the other clinical features. Since these are non-specific symptoms, it may be mistaken for a surgical abdomen. Kawai et al. report a case of CMPA presenting as HD. Barium enema had shown dilated colon with narrowing of the rectum and there was an increase in acetyl cholinesterase E (Ach-E) activity and eosinophils in the biopsy. Manometry was negative. Due to persistent symptoms, he underwent pull through, but the post-operative biopsy was negative for HD. He developed eczema and rashes after cow's milk and the RAST, raised IGE and lymphocyte stimulation test (LST) confirmed the diagnosis.[1] There are few other case reports of children with bloody diarrhea and narrowing of the colon suggestive of HD.[5] They have postulated that the false positive Ach-E staining could be due to the dysmotility caused by the immunological change resulting in an increase in nerve fibers.[1] This hypothesis has not been proved.

Recurrent NEC due to CMPA has been reported in a preterm neonate. They had noted a peripheral eosinophilia and recurrence of symptoms after commencing oral feeds, which settled with a hypoallergenic formula.[6] An in-utero sensitization has been proposed because of the early presentation.[7] An increased incidence of cow's milk allergy after intestinal surgery in newborns has also been noted. It is postulated to occur due to the immature intestinal mucosal barrier being breached early in life, resulting in an exaggerated immune response.[8]

CMPA can be either IgE mediated or non-IgE mediated. The IgE mediated form can be diagnosed by[1] raised IgE levels,[2] raised IgE levels specific to CM antigens otherwise known as IgE RAST,[3] stimulation index for CM by LST and[4] clinical response to the elimination of cow's milk.[8] In our patient, the IgE and RAST were very high and there was dramatic response to the elimination of cow's milk. Re-challenge with cow's milk has not been carried out due to the baby's clinical condition and the parents were unwilling.

This is the first case report from India of cow's milk allergy causing recurrent segmental enteritis leading to peritonitis. It is also unusual as it has occurred in the neonatal period. Our patient has not been breast fed and has had exposure to cow's milk soon after birth. It is possible that the NEC like a picture in the 1st week of life resulted in the intestinal mucosal barrier being breached, triggering allergy to cow's milk. CMPA should be considered in young infants on artificial feeds who present with a “surgical abdomen” and atypical clinical findings.