Respiratory Symptoms Mean Cow's Milk Allergy Lasts Longer in Children

A study presented at the 52nd annual scientific meeting of the American College of Allergy, Asthma, and Immunology made the strongest connection yet found between symptoms and lasting allergies. An article by Jennifer Reid Holman, Respiratory Symptoms Strongly Predict More Persistent Cow's Milk Allergy on Medscape reported on the study led by Alessandro Fiochi, MD, from the University of Milan Medical School in Italy.

Experiencing respiratory symptoms with the allergy, however — such as wheezing or runny nose — strongly predicts the likelihood that the allergy will persist considerably longer into childhood.

Holman wrote that:

The study included 153 children with confirmed immunoglobulin E (IgE)–mediated cow's milk allergy. Most of these children exhibited skin reactions to milk, such as eczema and hives. About half had asthma/rhinitis symptoms. Fewer than 25% experienced immediate gastrointestinal effects or anaphylaxis after ingesting cow's milk. Many children experienced 2 of these symptoms.
The median age of these children when they presented for allergy testing was 16 months (range, 1-186 months), and each child was followed with periodic challenges for an average of 31 months.

The researchers gathered data on several potential risk factors, including presenting symptoms, duration of exclusive breast-feeding, age when symptoms started, age when cow's milk was introduced to child's diet, level of milk-specific antibodies (IgE) generated, sensitization to dermatophagoides and eggs, the allergen dose that elicited a positive challenge, and the use of formula after the allergy diagnosis.

More than half of the children experienced a natural and complete remission of their cow's milk allergy during the study (median allergy duration, 18 months). Respiratory symptoms were the single strongest predictor of which children had a long-lasting allergy. Median duration of cow's milk allergy in these children was 41 months.

Presenting with anaphylaxis after ingesting milk was also strongly associated with a longer time to remission. Other significant but less strong predictors were reaction to low doses of the allergen during diagnostic testing and higher levels of specific IgE antibodies to the milk challenges.

The news that higher levels of antibodies predicts a persistent allergy reinforces an earlier study announced at the 25th Congress of the European Academy of Allergology and Clinical Immunology (EAACI) in Vienna, Austria, a study that made no news in the U.S. but one I reported on back on June 14, Big News! Test May Tell if Your Infant Will Always Be Allergic to Milk.

Holman's article went on to note that pediatricians often do not recognize that asthma symptoms can be due to food allergies. The venerable allergist Sami Bahna recommended that food allergy always be suspected as a cause.