Peanut Allergy: Earlier Exposure--Earlier Reactions

Study underscores the importance of prescribing self-injectable epinephrine for all children with potential food allergies.

With the banning of peanut butter and jelly from some school cafeterias, peanut allergies have become a popular topic in the media and the public. Discussions often include references to an increasing prevalence of allergies, as well as to an earlier emergence of those allergies in children.

In a study recently published in Pediatrics, Green and colleagues¹ investigated the characteristics of children with peanut allergies, including the age at first exposure to peanuts and at first allergic reaction. The authors conducted a retrospective chart review of 140 patients seen in the Duke University pediatric allergy and immunology clinic between July 2000 and April 2006. Half of the patients were born between 1988 and 1999; the other half were born between 2000 and 2005.

The authors considered a diagnosis of peanut allergy to consist of a clinical history consistent with an allergy as well as a positive result of skin or serum testing. Of the patients studied, 66% were boys; 82% had an atopic first-degree relative with either allergic rhinitis, asthma, food allergy, or atopic dermatitis; 68% were allergic to an additional food; 82% had a history of atopic dermatitis; 57% had allergic rhinitis; and 62% had asthma.

Patients in this study had received a diagnosis of peanut allergy by a physician who referred them to the allergy clinic. Self-injectable epinephrine had been prescribed for only 44% of these patients; 39% experienced an accidental peanut ingestion after the allergy was diagnosed.

The median age at first exposure to peanuts was 14 months; the first reaction occurred at a median age of 18 months. The median age at which patients were first seen in the allergy and immunology clinic was 28 months. Boys were seen at an earlier age than girls.

Patients born during or after 2000 were first exposed to peanuts at a median age of 12 months; this compares with 19 months in those born before 2000. Children born in or after 2000 had their first reaction to peanuts at a median age of 14 months, while those born before 2000 first reacted at a median age of 21 months. The time from first exposure to first reaction was not significantly different in the 2 groups.

This study indicates that children are being exposed to peanuts and are reacting to them at younger ages than in the past. Earlier reactions may be a consequence of earlier exposure. Although allergies may be more likely to be diagnosed because of an increased awareness among parents and physicians, the trend is still of concern. Also alarming is the finding that self-injectable epinephrine had been prescribed for fewer than half of the children referred for evaluation. This is especially worrisome given that many of the children reported accidental ingestions after diagnosis.

What are the implications for clinical practice? We should counsel parents to follow the AAP recommendations to hold off on peanut exposures until age 3 years in children with a family history of allergies.² The AAP also recommends that mothers of allergic children avoid exposure to peanuts while breast-feeding and, possibly, during pregnancy. In particular, we must make sure that all children with potential food allergies have access to self-injectable epinephrine. By doing so, we may be saving a child's life. *

References:

REFERENCES:

1.

Green TD, LaBelle VS, Steele PH, et al. Clinical characteristics of peanut-allergic children: recent changes.

Pediatrics.

2007;120:1304-1310.

2.

Zeiger RS. Food allergen avoidance in the prevention of food allergy in infants and children.

Pediatrics.

2003;111(6, pt 3):1662-1671.