The cow milk allergy complex: overlapping disease profiles in infancy.

Community based studies suggest reported reactions to cow's milk are very common in the first 12 months of life but many of them may not be reproduced on challenge. Recent laboratory based studies have identified three groups of infants with cow milk allergy (CMA) who demonstrate different symptom and laboratory profiles. The first, an IgE-sensitized group, shows features of immediate cutaneous eruptions and anaphylaxis. The second, a non-IgE sensitized group, develops gastrointestinal symptoms within hours of ingesting moderate amounts of cow milk, whereas the third group of patients shows symptoms of gastrointestinal disturbance with or without bronchitic and/or eczematous symptoms after ingesting cow milk over several hours or days. The late reacting non-IgE sensitized CMA patients demonstrate elevated T-cell reactivity in vitro to milk proteins. Hospital based studies, which are likely to reflect the more severe end of the spectrum of CMA, suggest adverse clinical reactions which persist longer may be associated with intolerance to a wide range of foods. Children with persistent CMA frequently develop eczema, asthma and rhinitis. Because of these complexities children with CMA should remain under the long term care of a medical practitioner familiar with the management of these problems. Medical practitioners responsible for the care of children with suspected CMA must be prepared to conduct cow milk challenges in a safe environment with facilities for resuscitation available. The notion that infants with suspected CMA should be referred to nutritionists and health workers for implementation of empirically devised low allergen diet programs without the diagnosis of CMA, being firmly established should be rejected. Where the diagnosis of CMA has not been made with certainty, parents may resort to unreasonable dietary restrictions.