What is the recommended approach for preventing nut allergies in pediatrics?

Peanut Allergy Prevention in Pediatrics

Early introduction of peanut-containing foods between 4-6 months of age is the cornerstone of peanut allergy prevention, with the specific approach determined by the infant's risk category based on eczema severity and egg allergy status. This paradigm shift, based on the landmark LEAP trial, has fundamentally changed how we approach food allergen introduction in infants 1, 2.

Risk-Stratified Approach to Peanut Introduction

High-Risk Infants (Severe Eczema and/or Egg Allergy)

For infants with severe eczema or egg allergy, introduce peanut-containing foods at 4-6 months of age, but only after allergy testing to guide safe introduction 1.

Testing Protocol Before Introduction:

• Measure peanut-specific IgE or perform skin prick testing (SPT) before any peanut introduction 1
• Peanut-specific IgE testing may be preferred initially in primary care settings to minimize delays and avoid unnecessary specialist referrals 1
• Do not order food allergen panels—test only for peanut to avoid poor positive predictive values that lead to unnecessary avoidance 1

Interpretation and Action Based on Test Results:

If peanut-specific IgE is <0.35 kUA/L:

• Risk of reaction is low (>90% will have negative SPT) 1
• Introduce peanut at home without supervision, or offer supervised feeding in office based on parental/provider preference 1

If peanut-specific IgE is ≥0.35 kUA/L:

• Refer to allergist for consultation and skin prick testing 1

If SPT wheal is 0-2 mm:

• Risk of allergy is low 1
• Introduce peanut at home or with office supervision based on preference 1

If SPT wheal is 3-7 mm:

• Risk of allergy is moderate to high 1
• Perform supervised feeding in office or refer for oral food challenge 1
• If no reaction occurs during supervised feeding, proceed with home introduction 1

If SPT wheal is ≥8 mm:

• Infant is likely allergic 1
• Keep under subspecialist care for assessment and monitoring 1

Moderate-Risk Infants (Mild to Moderate Eczema)

Introduce peanut-containing foods at approximately 6 months of age at home without prior testing or specialist evaluation 1, 3.

• Office supervision is not necessary but can be considered based on parental or provider preference 1
• No allergy testing is required before introduction 3

Low-Risk Infants (No Eczema or Food Allergies)

Introduce peanut-containing foods with other age-appropriate solid foods according to family and cultural preferences 1, 3.

• No specific timing requirement, testing, or supervision needed 3
• Can be introduced freely as part of complementary feeding 1

Safe Home Introduction Protocol

When introducing peanuts at home (for appropriate risk categories), follow these critical safety steps 1:

Timing and Environment:

• Feed only when infant is healthy—avoid if infant has cold, vomiting, diarrhea, or other illness 1
• Give first feeding at home, not at daycare or restaurant 1
• Ensure one adult can focus complete attention on infant for at least 2 hours after feeding 1

Introduction Technique:

• Offer small amount on tip of spoon first 1
• Wait 10 minutes 1
• If no reaction, slowly give remainder at infant's usual eating speed 1

Appropriate Peanut-Containing Foods:

The LEAP trial used approximately 2 grams of peanut protein (equivalent to 6 grams of peanuts) given 3 times weekly 1, 2. Options include 1:

• Bamba® peanut snacks: For infants <7 months, soften with 4-6 teaspoons water; older infants can have unmodified if managing dissolvable textures 1
• Thinned smooth peanut butter: 2 teaspoons mixed with 2-3 teaspoons hot water, stirred until dissolved and cooled 1
• Smooth peanut butter puree: 2 teaspoons mixed with 2-3 tablespoons pureed fruit or vegetables 1
• Peanut flour or powder: 2 teaspoons mixed with pureed foods 1

Critical Safety Caveats

Never give whole peanuts to children under 4 years of age due to choking risk 1. A concerning trend has emerged post-LEAP showing a tripling in peanut/tree nut aspiration rates at quaternary pediatric hospitals between 2015-2018, highlighting the urgent need for proper food preparation and supervision 4.

Recognize allergic reaction symptoms immediately 1:

• Mild: New rash, few hives around mouth or face 1
• Severe: Any combination of respiratory distress, vomiting, or systemic symptoms 1
• Call 911 for any concerning symptoms 1

Evidence Strength and Rationale

The LEAP trial provided Level 1 evidence demonstrating that early peanut introduction (4-11 months) reduced peanut allergy prevalence at 5 years from 13.7% to 1.9% in initially non-sensitized high-risk infants (81% relative risk reduction), and from 35.3% to 10.6% in those with initial mild sensitization 1, 2. This directly contradicts the pre-2008 avoidance recommendations and is supported by epidemiological data from Israel, where early peanut consumption correlates with low peanut allergy prevalence 1.

The NIAID expert panel guidelines (2017) represent the current standard of care and have been widely adopted, though implementation should consider societal norms regarding peanut consumption 1, 3. The guidelines acknowledge that in populations where peanuts are not widely consumed, early introduction could theoretically increase sensitization, though this remains largely theoretical 1.