Allergic Colitis Clinical and Endoscopic Aspects of Infants. with Rectal Bleeding Allergic Colitis is an inflammatory disorder of the colon which occurs mainly in preschool children. It is caused by an allergic reaction to food; most commonly cow s milk, egg, soya and/or wheat. It is nearly always associated with other conditions such as asthma, eczema and hayfever but may also occur in other children who have minor immunodeficiency states. Food allergy is important in most children attending hospital with colitis during the first 2 years of life. In children aged 2 weeks to 1 year, the most common form of colitis is allergic colitis, which results from hypersensitivity commonly to cow's milk and soy milk. Adverse reaction to cow s milk protein seems to affect upto 5-15% of infants while prevalence of cow s milk protein allergy vary from 2-7.5%. This diagnosis should be considered in breast fed infants with rectal bleeding without any effect on general health status.the so-called breast milk allergy is a status of food allergy induced in breastfed babies by heterologous proteins (typically cow's milk proteins) ingested by their mothers and appearing in their breast milk. The immunologic responses may vary from classic allergic mast cell activation to immune complex formation. Symptoms consist mainly of loose stools with flecks of blood often associated with abdominal pain or diarrhoea. Symptoms of milk protein allergy can be IgE mediated on non IgE mediated. IgE mediated symptoms result in an 1
immediate allergic reaction (Type 1 hypersensitivity) while non IgE mediated is likely to be multifunctional and includes immune complexes of IgA or IgG Ab bound to milk antigen (type III hypersensitivity reaction). This results is delayed reaction. (1) Reaction IgE mediated Non IgE mediated Respiratory Rhinoconjunctivitis Pulmonary haemosiderosis Asthma (Wheezing, cough) Laryngeal edema Otitis media Cutaneous Atopic dermatitis,urticaria, Contact rash / Atopic rash Angioedema GIT Oral allergy syndrome, Diarrhoea, vomiting, pain abdomen GER Enteropathy, enterocolitis syndrome, Colitis / Constipation/ FTT Allergic gastroenteropathy is manifested by symptoms including abdominal pain, vomiting, sporadic diarrhea. Food induced proctocolitis usually occurs in the first few weeks or months of life and is most often secondary to cow s milk or soya protein hypersensitivity. Infants usually have occult or gross blood in the stools with or without mucous. Aside from occasional apparent pain on defecation and a few infants with moderate eczema, systemic features are absent. Thus, in contrast to the infant with enterocolitis, features such as emesis, failure to thrive, significant anemia, and dramatic diarrhea are not seen. A definite diagnosis of food allergy requires a formal food challenge with or without endoscopy. However, in clinical practice, the diagnosis is often suspected,based on clinical symptoms with improvement after elimination of the offending protein from the diet of the infant with characteristic histology of the small bowel in patients with this disorder which includes a marked increase in the number of eosinophils in the 2
lamina propria, extensively hydrolyzed casein-based formula or the elimination of the protein from the diet of the mother of the breast-feeding infant, leading to clinical resolution of the bleeding within 72 to 96 hours. Other findings include hypoproteinemia, iron deficiency anemia and peripheral eosinophilia. On colonoscopy there is patchy regional erythema and haemorrhoagic erosions and microscopic eosinophilic and plasma cell infilteration of lamina propria (possibly with edema) which distinguish this condition from other type of colitis. Small Apthous ulcers seen with normal intervening mucosa on lower GI Endoscopy Study done by Hwang et al suggested advanced clinicopathological diagnostic criteria that facilitate the early confirmation of food protein-induced proctocolitis (FPIPC). Data of 38 FPIPC patients whose feeding pattern at onset of bleeding was exclusively breast-fed (94.7%) and formula-fed or mixed-fed (5.3%) and who had received sigmoidoscopy and biopsy, showed endoscopic abnormalities in all patients; nodular hyperplasias with circumscribed and/or central pit-like erosions in 94.7% and erythema in 5.3%. Allergic colitis was defined histologically as colonic mucosa with 3
>or= 6 eosinophils per high power field and/or eosinophils in colonic crypts or mucularis mucosa. (2) Histopathological findings were; lymphoid aggregates in 94.7%, eosinophils in lamina propria of >or=6 cells/ HPF in 97.4% and of >20 cells/hpf in 63.2%, epithelial or muscularis mucosa eosinophil infiltration in 97.4%, and crypt abscess in 2.6%.(2) In another study 56 Ohio NASPGHAN members were surveyed to determine standard practice regarding the evaluation of rectal bleeding in infants. All infants underwent flexible Multiple eosinophils seen in high power view of rectal mucosa. H & E stain sigmoidoscopy with biopsies and found that 64% infants with rectal bleeding had allergic colitis, Five (23%) had normal biopsies and three (14%) had nonspecific colitis. Rectal bleeding in all infants with normal biopsies or nonspecific colitis resolved without diet change which proved that a significant proportion of infants with rectal bleeding may not have allergic colitis and may undergo unnecessary, expensive formula or maternal diet changes that may discourage breast-feeding.(3) On the contrary study done by Armesen Pedrejone A et al concluded that food protein allergy is the most probable diagnosis in an infant with bloody stool and colonoscopy and histopathological study of three biopsy specimen is required for the diagnosis (4). Differential diagnosis for eosinophilic gastrointestinal disorders characterized by eosinophilic infiltration and inflammation of the GIT in the absence of previously 4
identified causes of eosinophilia are parasitic infection, malignancy, collagen vascular disease, drug sensitivities and IBD. In last few years, a increasing number of cases have been seen in exclusively breast fed babies also. Allergic colitis is a temporary disorder of early infancy. It might progress to classical IBD, so becoming are intermittent but life long problem or it may completely resolve. The features that distinguish colitis caused by food allergy from classical IBD are macroscopic appearance at colonoscopy and histopathological features of colonic biopsy specimen; complete remission on an appropriate elimination diet,association with atopy and no family history of IBD. When some doubt remains as to the presence of food allergy, proctosigmiodoscopy in conjunction with evaluation of multiple mucosal biopsy specimens may be helpful for diagnosis.(5,6) Treatment is by elimination diet which is started once suspicion is there. Offending food should be removed from the diet.for milk protein intolerance. Adverse reaction to soy protein have been reported in 10-35% of infants with CMPA. Particularly infants with multiple food allergy and eosinophilic enterocolitis syndrome react to formulas which include soya protein.partially hydrolysed, extensively hydrolysed and amino acid formulas are there which can be used in a staged manner. By 1 year of age the infants routinely tolerate an unrestricted diet, and the long term prognosis is excellent. References : 1. Brill H. Approach to milk protein allergy in infants. Can Fam Physician 2008;54:1258 64 5
2. Hwang JB, Park MH, Kang YN, Kim SP, Suh SI, Kam S. Advanced criteria for clinicopathological diagnosis of food protein-induced proctocolitis. J Korean Med Sci. 2007 Apr;22(2):213-7 3. Xanthakos SA, Schwimmer JB, Melin-Aldana H, Rothenberg ME, Witte DP, Cohen MB. Prevalence and outcome of allergic colitis in healthy infants with rectal bleeding: a prospective cohort study. J Pediatr Gastroenterol Nutr. 2005 Jul;41(1):14-5. 4. Armisén Pedrejón A, Sancho Madrid B, Almaraz Garzón E, Prieto Bozano G, Polanco Allué I. Colitis induced by a food allergen. A report of 20 cases. An Esp Pediatr. 1996 Jan;44(1):21-4. 5. Machida HM, Catto Smith AG, Gall DG, Trevenen C, Scott RB. Allergic colitis in infancy: clinical and pathologic aspects. J Pediatr Gastroenterol Nutr. 1994 Jul;19(1):22-6. 6. Lake AM. Food-induced eosinophilic proctocolitis. J Pediatr Gastroenterol Nutr. 2000;30 Suppl:S58-60 6