Allergic Proctocolitis: Literature Review and Proposal of a Diagnostic-Therapeutic Algorithm

Abstract

Allergic proctocolitis (AP) is a benign condition, frequent in childhood, that is classified as a non-IgE-mediated food allergy. The prevalence is unknown; however, its frequency appears to be increasing, especially in exclusively breastfed infants. Clinical manifestations typically begin in the first few months of life with the appearance of bright red blood (hematochezia), with or without mucus, in the stool of apparently healthy, thriving infants. Most cases of AP are caused by cow's milk proteins; however, other allergens, such as soy, egg, corn, and wheat, may be potential triggers. Diagnosis is based on the patient's clinical history and on the resolution of signs and symptoms with the elimination of the suspected food antigen from the diet and their reappearance when the food is reintroduced into the diet. The treatment of AP is based on an elimination diet of the trigger food, with resolution of the symptoms within 72-96 h from the beginning of the diet. The prognosis of AP is good; it is a self-limiting condition, because most children can tolerate the trigger food within one year of life, with an excellent long-term prognosis. The purpose of this review is to provide an update on the current knowledge and recommendations in epidemiological, diagnostic, and therapeutic terms to the pediatricians, allergists, and gastroenterologists who may find themselves managing a patient with AP.

Keywords: allergic proctocolitis; elimination diet; food allergy; non-lgE food allergy; rectal bleeding.

Figure 1

Proposed algorithm for diagnosis and treatment of allergic proctocolitis. Legend: AAF = amino acid formula; CM = cow’s milk; eHF = extensively hydrolyzed formula. # Under the supervision of a dietitian. ^ At home if skin prick test to trigger food is negative; in hospital setting if the skin prick test to trigger food is positive. * To change from an AAF directly to a cow’s milk infant formula, except in selected cases where one may consider changing AAF to eHF as an interim step before cow’s milk formula.