Randomized Trial of Peanut Consumption in Infants at Risk for Peanut Allergy

Kristi Tinsbloom, PharmD candidate 2015, Mercer University College of Pharmacy

The incidence of peanut allergy is increasing in children. In fact, according to a study commissioned by FARE (Food Allergy Research & Education), the prevalence of peanut allergy in children in the United States has tripled from 1997 to 2008. In allergic individuals, peanuts can cause a severe, possibly fatal, reaction known as anaphylaxis. Peanuts are considered legumes as they grow underground and are not related to other nuts, such as almonds and cashews, which grow on trees. Therefore, allergy to peanuts does not confer an allergy to other nuts.1

A recently published study addressed the hypothesis that exposing children who are at high risk for an allergy to peanuts at an early age could decrease the likelihood that they would develop the peanut allergy.2

Title: Randomized Trial of Peanut Consumption in Infants at Risk for Peanut Allergy2
Design Randomized, open-label, controlled trial; 628 participants
Objective To determine which strategy is most effective in preventing the development of peanut allergy in infants at high risk for the allergy
Study groups Four groups (two cohorts):
• Peanut avoidance (skin test negative)
• Peanut consumption (skin test positive)
• Peanut avoidance (skin test negative)
• Peanut consumption (skin test positive)
Methods Infants with severe eczema and/or egg allergy were randomly assigned to either consume or avoid peanuts until 60 months of age. Participants between the ages of 4 and 11 months at randomization were assigned to separate study cohorts based on their preexisting sensitivity to peanut extract; this was determined by a skin-prick test. Participants in this age group with a measurable wheal of 1 to 4 millimeters in diameter were placed in one study group, while those with no measurable wheel were placed in another.
Duration Enrollment from December 2006 through May 6, 2009
Primary Outcome Measure Proportion of participants with peanut allergy at 60 months of age determined by an oral food challenge
Baseline Characteristics • Median age was 7.8 months
• Mean age was 7.8 months
Results The prevalence of peanut allergy at 60 months of age was 13.7% in the avoidance group and 1.9% in the consumption group (p<0.001). The absolute risk difference was 11.8% (p<0.001) representing and 86.1% relative reduction in the prevalence of peanut allergy. There were 98 participants who had an initial positive test; among this cohort, 35.3% in the avoidance group had peanut allergy compared with 10.6% in the consumption group (p=0.004).
Adverse Events Common Adverse Events: upper respiratory tract infection (69.6% in consumption group, 58.3% in avoidance group), varicella (50.8% in consumption, 44.5% in avoidance), gastroenteritis (63.6% in consumption, 53.0% in avoidance), urticarial (22.6 in consumption, 12.5% in avoidance), rash (11.9% in consumption, 14.0% in avoidance)
Note: all adverse events were considered mild in severity
Serious Adverse Events: None reported
Percentage that Discontinued due to Adverse Evens: 0%
Study Author Conclusions Introducing peanuts at an early age decreased the frequency of the development of peanut allergy in children at high risk for the allergy and modulated immune response to peanuts. Participants with a negative baseline skin test showed a 86% reduction in the prevalence of peanut allergy, while those in the positive baseline skin test showed a reduction of 70% at 60 months of age.

This study shows promise for decreasing the incidence of peanut allergy in children at high risk. Perhaps removing allergenic foods from the diet of infants and their mothers during pregnancy and lactation is actually not the way to go in preventing the development of allergies. The results of this study speak to the potential of exposure to allergens at a very early age having a positive impact for prevention of allergy development.

References
1. Peanut Allergy. Food Allergy Research and Education (FARE). http://www.foodallergy.org/allergens/peanut-allergy. Accessed February 26, 2015.

2. Du toit G, Roberts G, Sayre PH, et al. Randomized Trial of Peanut Consumption in Infants at Risk for Peanut Allergy. N Engl J Med. 2015; doi: 10.1056/NEJMoa1414850.

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s