Diagnosis of cow's milk allergy in children: determining the gold standard?

Abstract

Cow's milk protein allergy (CMPA) affect many organs, from mouth to gut, with, immediate and delayed reactions, including infantile colic, food protein induced enterocolitis syndrome, enteropathy, eosinophilic disorders, among which infantile proctocolitis, and "dysmotility" disturbances, gastro-esophageal reflux and constipation. Diagnosis follows usual steps, careful history taking and medical examination, before starting an elimination diet, for diagnosis and treatment. Beyond, laboratory tests may help, but definitive conclusion will arise from the oral food challenge. The double-blind-placebo-controlled-food challenge, the "gold standard", is needed in clinical research. The food challenge includes the progressive at-home reintroduction of milk, all the more needed since most cases of CMPA in infants are delayed: in clinical practice, diagnosing CMPA is more than saying if the child reacts to cow's milk. One has to define the syndrome the child is suffering from, the risk implied, the best replacement formula. When tolerance develops, a second diagnostic procedure allows seeing if the child has outgrown his disease and, if not, what is the expected outcome and which type of food is best adapted: small amounts of milk, or transformed forms, such as baked milk. Primary care practice is adapted to non-IgE mediated CMPA. When CMPA is part of multiple food allergies or of an eosinophilic disorder, referral centers will perform multiple allergy testing, endoscopic procedures and complex dietary guidance.