Best of Allergy Articles 2021 -Cow’s Milk Allergy/Allergic proctocolitis (Part 4)

In Pediatrics, supplement 3 summarizes 76 articles: Synopsis Book: Best Articles Relevant to Pediatric Allergy, Asthma and Immunology

Some of the studies that are most relevant to pediatric GI doctors I am reviewing for this blog over the next/past few days.

A Lemoine et al. Clin Exp Allergy  2021:51(9):1242-1245.  doi:10.1111/cea.13896. Rectal bleeding and cow’s milk protein-induced allergic proctocolitis: A prospective study

In this prospective cohort of infants (in France) with food protein-induced allergic proctocolitis (FPIAP) (n=76), all infants had rectal bleeding (RB) which resolved with cow’s milk protein (CMP) elimination. After the initial oral food challenge (OFC) which took place 2 to 8 weeks after resolution of rectal bleeding, OFC was repeated every 2 months.

Key findings:

  • Only 31% failed the initial OFC
  • The median age of tolerance, for those with a confirmed FPIAP based on OFC, was 6.8 months, with >75% of the cohort tolerant by 10 months of age

My take:

  1. This study shows that the majority of infants with RB probably do not have FPIAP. In those that do have FPIAP, earlier challenge is reasonable in the majority.
  2. FPIAP is generally mild and self-limited. Diagnosis is hampered by lack of validated criteria.
From Siesta Key, FL

One more cause of rectal bleeding

Two articles in this month’s JPGN, along with the editorials, make it clear that when patients are having rectal bleeding, we should ask if they are spending an inordinate amount of time straining on the toilet.  (JPGN 2012: 54: 263-65, 266-70, 167-68, 169-70).  This question may help uncover Solitary Rectal Ulcer Syndrome (SRUS).

This syndrome which is often a misnomer because many cases have erythema rather than ulcers; and, lesions can be ulcerative or polypoid.  They can be single or multiple involving the distal rectum.  SRUS often has a delayed diagnosis, 1.7 years and 3.2 years respectively in the two studies.  The differential diagnosis includes polyps, infections, IBD, abuse, and rectal manipulation.  Histology features include muscularinization of lamina propia, mixed inflammatory infiltrate, thickened muscularis mucosa, and epithelial hyperplastic changes.

Treatment includes avoidance of straining/behavior modification, use of laxatives, and perhaps topical mesalamine.

Additional references:

  • -Gastroenterol Clin North Am 2008; 37: 645-68. Rectal disorders/SRUS -review.
  • -Gastrointest Endosc 2005; 5: 755-62,
  • -Eur J Gastroenterol Hepatol 2008; 2: 89-92. SRUS in children.
  • -Gut 2004; 53: 368-70.  Biofeedback for SRUS.
  • -Pediatrics 2002; 110: e79.
  • -Clinical Perspectives in Gastroenterology 1999; 2: 190.