Does early introduction of peanut butter decrease the risk of peanut allergy (Arachis hypogaea allergy)?

From the Guidelines

Introducing peanut butter early in a child's diet can significantly decrease the risk of developing a peanut allergy, with current guidelines recommending introduction as early as 4-6 months of age, depending on risk factors. The most recent and highest quality study, the LEAP trial 1, demonstrated an 11-25% absolute reduction in the risk of peanut allergy in high-risk infants when peanuts were introduced between 4 and 11 months of age. This trial showed that early exposure to peanut proteins helps the developing immune system recognize them as harmless, rather than dangerous invaders.

Key Considerations for Introduction

• For high-risk infants (those with severe eczema or egg allergy), introduction should occur around 4-6 months 1.
• For moderate-risk infants (mild to moderate eczema), introduction should occur around 6 months 1.
• For low-risk infants, introduction can occur according to family preferences after 6 months 1.
• When introducing peanut butter to infants, use a thin layer mixed with infant cereal or pureed fruit, or use peanut powder or peanut butter diluted with water to create a consistency that won't be a choking hazard 1.
• Start with a small amount (¼ teaspoon) and gradually increase if no reactions occur 1.

Monitoring and Safety

• The first exposure should ideally happen at home during the day (not before bedtime) when the infant is healthy and an adult can monitor for any reactions for at least 2 hours 1.
• Breastfeeding recommendations suggest that early introduction of peanut may not affect the duration or frequency of breastfeeding, and does not influence growth or nutrition 1.
• If the 4 to 6 month time window is missed for any reason, infants may still benefit from early peanut introduction, but older age at screening is associated with larger wheal diameter peanut SPT and hence a higher likelihood of established peanut allergy 1.

Guidelines and Recommendations

• The National Institute of Allergy and Infectious Diseases (NIAID) published addendum guidelines 1 that categorize infants into 3 categories based on risk factors, and provide recommendations for introduction of peanut-containing foods.
• The European Society for Pediatric Gastroenterology, Hepatology, and Nutrition (ESPGHAN) also recommends introducing allergenic foods, including peanuts, when complementary feeding is commenced, around 4 months of age 1.

From the Research

Introduction to Peanut Allergy Prevention

• The introduction of peanut butter at an early age has been studied as a potential method for decreasing the risk of peanut allergy in infants.
• Research has shown that early introduction of peanut protein can be beneficial in preventing peanut allergy, but the optimal timing and approach are still being studied.

Studies on Early Peanut Introduction

• A study published in 2021 2 explored pediatrician beliefs and practices regarding peanut introduction and testing, and found that barriers to recommending early peanut introduction included lack of awareness, lack of agreement, lack of resources, and lack of outcome expectancy.
• Another study published in 2023 3 found that introducing peanut at an age of 8 months or later in infants with moderate and severe eczema resulted in an increased risk of reactions to peanut, suggesting that peanut should be introduced before 8 months to reduce this risk.
• A 2012 study 4 discussed the rising incidence of peanut allergy and the importance of management strategies, including carrying and properly administering self-injectable epinephrine.

Factors Associated with Reactions to Peanut

• A 2023 study 5 identified risk factors for home epinephrine-treated reactions during peanut and tree-nut oral immunotherapy, including previous reaction severity and reaction treated in an emergency department before starting oral immunotherapy.
• Another 2023 study 6 found that among US parents/caregivers, 47.7% believed that feeding peanuts early prevented peanut allergy, and that primary care provider counseling was a significant facilitator for peanut introduction before 7 months.

Awareness and Practices Among Parents and Caregivers

• The 2023 study 6 also found that awareness of the Prevention of Peanut Allergy Guidelines was low among parents/caregivers, with only 13.3% reporting awareness, and that disparities existed in terms of demographic characteristics and food allergy/eczema status.
• The study suggested that future efforts to increase guideline adherence need to address disparities, provide support for medical providers, and educate about the true incidence of reactions.