Food allergy, anaphylaxis, dermatology, and drug allergy
The natural history of IgE-mediated cow's milk allergy

https://doi.org/10.1016/j.jaci.2007.08.023Get rights and content

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.

Section snippets

Methods

This is a retrospective review of the clinical records of 4117 patients seen by the principal investigator (R.A.W.) at 2 pediatric allergy clinics, 1 private and 1 university-based, between 1993 and present. There were 1368 with food allergy, of whom 1073 were diagnosed with milk allergy. Two hundred thirteen patients with milk allergy were not included in the analysis because they were only seen once and the visit was before 2004, making the likelihood of at least 1 follow-up unlikely, and an

Study population

Eight hundred seven patients with IgE-mediated CMA were included (Table II). There was a 2:1 male:female ratio, with age at the initial visit ranging from 1 month to 209 months (median, 13 months). The median duration of follow-up was 54 months, and the median number of visits was 5. Other atopic conditions were common (49% had asthma, 40% had allergic rhinitis, and 71% had eczema by the time of their most recent follow-up visit). Most patients (91%) had at least 1 other food allergy; egg and

Discussion

In this referral population of children with milk allergy, the prognosis for developing tolerance is worse than previously estimated. Using 3 sets of increasingly broad criteria to define tolerance, incidence rates of tolerance at 4 years ranged from <1% to 26% in our study, substantially lower than previously reported. Our findings stand in marked contrast to the study that is most often quoted, which found that 75% of children with IgE-mediated milk allergy were tolerant by the age of 3 years.

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

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.

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