Natural course of cow's milk allergy in childhood atopic eczema/dermatitis syndrome

OBJECTIVE: This review was undertaken to determine the role of adverse reactions to bovine proteins in atopic dermatitis, recently called atopic eczema/dermatitis syndrome (AEDS).

DATA SOURCES: A PubMed literature search was conducted with use of the following phrases: atopic dermatitis and food allergy, atopic dermatitis and cow's milk, and cow's milk and eczema.

STUDY SELECTION: The authors' judgment and personal interest guided the literature selection.

RESULTS: Food allergy has a role in at least 20% of the cases of AEDS in children younger than 4 years. Cow's milk is usually the first food given to an infant, and cow's milk hypersensitivity is often the first symptom of an atopic condition. Adverse reactions to cow's milk proteins are usually categorized as immunoglobulin (Ig)E-mediated or non-IgE-mediated cow's milk allergy and nonallergic hypersensitivity (intolerance); the symptoms do not allow differentiation of these entities. In patients with cow's milk allergy and AEDS, resolution occurs in 90% by the age of 4 years. Non-IgE-mediated cow's milk allergy often disappears before the age of 1 year. Associated reactions to other foods develop in approximately 45% of patients. Allergy to potential environmental inhalant allergens has been reported in up to 28% of patients by 3 years of age and up to 80% before puberty. After consumption of large amounts of cow's milk, 45% of 10-year-old children who had become tolerant of cow's milk, but also 15% of control subjects, still had gastrointestinal complaints. The presence of cow's milk allergy during infancy increases the risks for development of other food allergies, respiratory atopy, and persistence of AEDS.

CONCLUSION: Adverse reactions to bovine proteins have an important role in AEDS.