What Is Allergic Proctocolitis?
Food protein-induced allergic proctocolitis (FPIAP) or allergic proctocolitis is also known as allergic or eosinophilic proctocolitis or protein intolerance in the past. It is a type of delayed inflammatory non-IgE mediated gut food allergy. It is commonly seen in young infants within the first weeks of their life, and, in most cases, it resolves by late infancy. The affected child will have blood-tinged stools (hematochezia). Therefore, it is the common cause of rectal bleeding in young individuals. Blood loss is typically minimal but can occasionally produce anemia or hypoalbuminemia.
What Are the Symptoms of Allergic Proctocolitis?
Symptoms of allergic proctocolitis will usually start at the initial few weeks of age and range from blood seen with mucus in bowel movements, blood-stained loose stools, or diarrhea. Systemic manifestations of allergic emesis, dramatic diarrhea, or abdominal distention are rare and may suggest other allergic disorders of the gastrointestinal tract. The affected child will have hematochezia, where there will be fresh bleeding in the stools. Patients with allergic proctocolitis often do not have weight loss, impairment of the general state, or changes in palpation of the abdomen. Early detection and a proper nutrition intervention will help the infant maintain the growth rate and promote the complete resolution of the symptoms.
What Are the Causes of Allergic Proctocolitis?
Allergic proctocolitis is a condition secondary to an allergy to formula, food, or breast milk. FPIAP mostly occurs in breastfed infants, and cow's milk or soy-based formula milk can also be a main triggering agent. If the condition is due to breast milk, the infant may be allergic to a component present in the mother's diet, which passes to the child via breast milk. In this case, the treatment of allergic proctocolitis involves dietary manipulation to eliminate the offending agent.
Arachidonic acid (AA) (polyunsaturated fats) present in the infant formulas is a principal precursor of various inflammatory cytokines. A study stated that Arachidonic acid might trigger allergic reactions by further fueling the inflammation. Scientists have also illustrated the development of allergic colitis in an infant fed with AA.
But still, more studies are required to determine the effect of AA and docosahexaenoic acid and whether they carry risks that outweigh the benefits. Inflammation of the rectum and distal sigmoid colon, known as allergic proctocolitis, is mainly induced by the dietary proteins excreted in the mother's milk. The breastfed infants with allergic proctocolitis are generally healthy other than the presence of blood within the stool.
What Is the Differential Diagnosis of Allergic Proctocolitis?
The causes of rectal bleeding in childhood may be heterogeneous; therefore, it is necessary to exclude various other conditions in young infants that cause rectal bleeding in the young age group.
It includes:
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Infection.
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Rectal bleeding.
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Intestinal intussusception.
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Inflammatory bowel disease.
How to Diagnose Allergic Proctocolitis?
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Allergy tests that include skin or blood tests for Immunoglobulin E (IgE) antibodies are usually negative for infants with allergic proctocolitis; therefore, they are not recommended.
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Proctoscopic examination.
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Biopsies of the rectum and lower sigmoid.
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Sigmoidoscopy and colonoscopy with multiple biopsies help implement further evaluation of the patients. These tests are usually recommended for patients with atypical symptoms like severe rectal bleeding or anemia instead of a cow's milk elimination diet trial.
How to Treat Allergic Proctocolitis?
Diet Change in Infants:
The management of allergic proctocolitis usually depends on the duration of bloody stool (hematochezia). When the duration of bloody stool is less than one month, the doctors will suggest waiting for the spontaneous resolution without eliminating the offending food. If it is more than one month, elimination of the offending food is recommended. Sometimes, even after eliminating the offending food the hematochezia may reappear, in that case the offending food is further eliminated for the next three months. Improvement of the symptoms is usually seen within three to seven days, but it may occur after two weeks. If there is no improvement, the diet is changed to a protein hydrolysate formula (PHF) and elemental l-amino acid (LAA) formula in bottle-fed babies. Compared to formula milk (which resembles breast milk), breast milk is naturally hypoallergenic. Switching to a soy-based formula is not usually recommended because children sensitive to cow's milk are also sensitive to soy protein. This combined sensitivity mostly occurs in at least 15 % of infants, reported earlier as high as 40 %.
Diet Change in Breastfeeding Women:
In breastfeeding women, cow's milk and all dairy products should be removed from her diet with the advice of a dietician. Most cases will resolve with the elimination of cow's milk within 48–72 hours. But, if symptoms do not resolve, further changes to the breastfeeding mother's diet by consulting a doctor. Once symptoms have resolved, the doctor may reintroduce the eliminated foods into the breastfeeding mother's diet to confirm the offending food/s.
Suppose more than one food protein is eliminated from the mother's diet. In that case, it should be supervised by a dietician to ensure nutritional adequacy to prevent excess weight loss in the mother. The mother's diet should contain an additional serving of protein and a multivitamin like Vitamin B2 (riboflavin) if it contains only a nut, grain, or coconut milk substitute. During breastfeeding, maternal calcium requirements of 1,000 mg/day can be supplied with 800mL/day of calcium-fortified cow's milk replacement like soy, rice, almond, or oat milk. When this is not possible, calcium supplements may be recommended.
When Will Allergic Proctocolitis Get Resolved?
Allergic proctocolitis usually occurs in the first six months of life in 50 % of infants and the ninth month in 95 % of infants. Therefore, it is recommended to reintroduce the food that causes allergy to the mother's or infant's diet after avoiding it for six months or at 12 months of age. For infants with severe symptoms like blood-stained diarrhea, the offending foods should be gradually introduced under the supervision of a dietitian. Elimination of the protein that causes allergy from the infant's diet, with an extensively hydrolyzed casein-based formula or by eliminating the protein from the breastfeeding mother's diet.
Conclusion
Allergic proctocolitis is a non-IgE-associated disease, and the method of treating it is by eliminating presumed triggering antigens. Following the above techniques can lead to clinical resolution of the bleeding within three to four days. And by age one, the infants will develop to tolerate an unrestricted diet with excellent performance.
