Allergic response to CMP (cow’s milk proteins) in infants has been acknowledged among paediatricians for centuries. It is considered to be the first oral allergy experience in infants in the Western World. Whilst CMP will provoke an immune response in all infants, there are only a small number of cases that develop CMA (cow’s milk allergy). It has been confirmed that introduction to CMP (via CMP based formula or cow’s milk as a stand-alone product) within the first 3 months of life results in heightened humoral responses.
CMA affects 2–3% of infants and symptoms are diverse, non-specific, and similar to other childhood diseases. Common symptoms of CMA include atopic dermatitis, vomiting, colic, diarrhoea and wheezing, and in rare cases may cause an anaphylactic response. Given the fatal nature of anaphylaxis, it comes as no surprise that implementation of a CMP elimination diet is common in suspected CMA sufferers. However, less than half of infants that appear symptomatic to CMP are confirmed with the allergy. The prognosis is good for confirmed cases of CMA with 92% of these individual’s having recovered by 10 years of age.
Two sub-classes of CMA sufferers have emerged – IGE-mediated (positive to skin prick allergy test and present with immediate acute CMA symptoms upon exposure to CMP) and Non IGE-mediated (negative to skin prick allergy test and present with intermediate to late acute CMA symptoms after exposure to CMP). The “gold standard” for CMA diagnosis is the DBPCFC (double-blind placebo-controlled food challenge). The DBPCFC method involves the patient consumption of two samples (one containing CMP, and the other CMP free) on separate days. The results of this method can determine both sub-classes of CMA sufferers.
It is critical for parents to gain a positive CMA diagnosis for their infant, as an unnecessary CMP elimination diet may lead to other problems including nutritional inadequacy, growth retardation, eating disorders and psychosocial problems. Furthermore, those confirmed positive to CMA should be assessed to determine the MED (minimum elicited dosage) required to produce such a symptomatic response. The MED data can be used to educate parents on accurate assessment of food labelling in direct comparison to the infant’s threshold. As there is no known treatment for confirmed CMA, seeking dietary assistance is key in ensuring a well-balanced diet is introduced to the infant providing sufficient calcium and nutrients. Introductory amounts of CMP may be implemented based upon the individual’s MED level and may assist with desensitization.