The natural history of IgE-mediated cow's milk allergy

Skripak, Justin M. MD
Matsui, Elizabeth C. MD, MHS
Mudd, Kim RN
Wood, Robert A. MD

Department of Pediatrics, Division of Allergy and Immunology, Johns Hopkins University School of Medicine, Baltimore, Md.

Reprint requests: Robert A. Wood, MD, CMSC 1102, Johns Hopkins Hospital, 600 North Wolfe St, Baltimore, MD 21287. Email: [email protected]

Supported by National Institutes of Health Training Grant #5T32 AI07007 and the Eudowood Foundation.

Received for publication May 21, 2007; revised August 8, 2007; accepted for publication August 8, 2007.

Disclosure of potential conflict of interest: R. A. Wood has consulting arrangements with Dey Pharmaceutical, has received grant support from Merck and Genentech, and is on the speakers' bureau for Dey, Merck, and Glaxo. The rest of the authors have declared that they have no conflict of interest.

Journal of Allergy & Clinical Immunology 120(5):p 1172-1177, November 2007.

Background

Cow's milk allergy (CMA) is the most common food allergy in infants and young children, affecting 2% to 3% of the general population. Most studies have shown the prognosis of developing tolerance to cow's milk to be good, with most outgrowing their allergy by age 3 years.

Objective

To define the natural course of CMA and identify the factors that best predict outcome in a large referral population of children with CMA.

Methods

Clinical history, test results, and final outcome were collected on 807 patients with IgE-mediated CMA. Patients were considered tolerant after they passed a challenge or experienced no reactions in the past 12 months and had a cow's milk IgE (cm-IgE) level <3 kU/L.

Results

Rates of resolution were 19% by age 4 years, 42% by age 8 years, 64% by age 12 years, and 79% by 16 years. Patients with persistent allergy had higher cm-IgE levels at all ages to age 16 years. The highest cm-IgE for each patient, defined as peak cm-IgE, was found to be highly predictive of outcome (P < .001). Coexisting asthma (P < .001) and allergic rhinitis (P < .001) were also significant predictors of outcome.

Conclusion

The prognosis for CMA in this population is worse than previously reported. However, some patients developed tolerance during adolescence, indicating that follow-up and re-evaluation of CMA patients is important in their care. cm-IgE level is highly predictive of outcome.

Clinical implications

The increasing potential for persistence of CMA, along with cm-IgE level's effect on prognosis, should be considered when counseling families regarding expected clinical course.