Eczema Associated With Heightened Risk of Peanut Allergy in Infants

In a cohort of pediatric patients with moderate to severe eczema, researchers found that infants with more severe disease are at a heightened risk of allergic reactions during their first introduction to peanuts.

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In a recent study,¹ researchers sought to examine the optimal timing of introduction to peanuts in children. They cited a prior study, the Learning Early About Peanut allergy (LEAP) study, which supported a reduction in peanut allergies when introduction took place between 4 months and 11 months of age, as opposed to avoidance.

“However, since the LEAP study protocol excluded 76 infants with >4-mm wheal to peanut in skin prick tests, the optimal timing of introduction and the risk of introducing peanut in highly sensitized patients remains unresolved,” study authors wrote.

The new study, conducted in the Netherlands and known as the PeanutNL study, included pediatric patients (n=707) between the ages of 4 and 12 months who had been brought in as patients to one of several pediatric allergology centers involved in the study. All participants were required to have moderate-to-severe eczema as determined by a SCORAD score of equal to or greater than 15. Of all participants, 12% had mild eczema, 41% had moderate eczema, and 35% had severe eczema.

Furthermore, they were required to have demonstrated a prior immediate reaction to another food or have a direct family member with a history of systemic reactions to peanut exposure.

Researchers conducted skin prick tests using either in-house produced peanut extract or commercial whole-peanut extract. All participants underwent a process of dose escalation with 30-minute periods and a 60-minute observation period for the final dose stage:

• 0-mm wheal to peanut: 2-step challenge (200 and 2000 mg of peanut protein)
• 1- to 4-mm wheal to peanut: four-step challenge (100, 300, 1000, and 2000 mg of peanut protein)
• >4-mm wheal to peanut: eight-step challenge (1, 3, 10, 30, 100, 300, 1000, and 3000 mg of peanut protein)

Introductions that were free of reactions (negative challenge) required patients’ parents to conduct a secondary introduction of peanuts at home for 6 months. Positive reactions, or a diagnosable peanut allergy, was identified in 9.5% of infant participants.

Researchers then assessed factors associated with or not associated with peanut reactions. Factors not associated with a reaction to peanuts included duration of eczema exacerbations, number of family members with atopic disease, type of atopic disease, wheezing, prior reaction to cow’s milk, and partial breastfeeding.

However, both age and severity of eczema were associated with peanut allergies, particularly as independent risk factors for an allergic reaction at introduction.

“There were 6 infants with peanut allergy at first introduction without having eczema. Therefore, other risk factors may be involved besides age and severity of eczema in a minority of cases. These may include impaired skin barrier without inflammation, genetic factors (since five out of six had family members with (pea)nut allergies), or gastrointestinal barrier impairments,” study authors wrote. “In conclusion, this study shows that age ≥8 months and severe eczema are independent major risk factors for having reactions to peanut at first introduction. Infants with atopic dermatitis in high peanut consumption countries may therefore benefit from the introduction of peanut.”

Reference

1. Verhoeven DH, Herpertz IC, Hol J, et al. Reactions to peanut at first introduction in infancy are associated with age ≥8 months and severity of eczema. Pediatr Allergy Immunol. 2023;34(6). doi:10.1111/pai.13983