Promoting Tolerance to Peanut in High-Risk Children (LEAP)

• Effect of peanut consumption or avoidance on other allergy outcomes [ Time Frame: 30 and 60 months ] [ Designated as safety issue: Yes ]
• safety of peanut consumption among study participants [ Time Frame: 60 months ] [ Designated as safety issue: Yes ]
• immunologic mechanisms by which consumption of a peanut-containing snack may induce tolerance to peanuts [ Time Frame: 60 months ] [ Designated as safety issue: No ]

• Effect of peanut consumption on other allergy outcomes
• safety of peanut consumption among study participants
• immunologic mechanisms by which consumption of a peanut-containing snack may induce tolerance to peanuts

This study will evaluate whether early exposure to peanuts promotes tolerance and provides protection from developing peanut allergy in children who are allergic to eggs or who have severe eczema.

Allergic reactions to peanuts are potentially life-threatening and, in some children, can result from ingestion of only trace quantities of peanuts. At highest risk are children with eczema or who are allergic to eggs; these children have a 20% chance of developing peanut allergy by the age of five. The majority of children allergic to peanuts have their first reaction between the ages of 14 and 24 months, often at the time of their first exposure to peanut. Currently, there is no cure for peanut allergy.

Peanut allergy has become an increasingly common problem in early childhood in the United States and the United Kingdom. Despite current public health guidelines in both countries recommending the avoidance of peanut consumption in the first years of life, the proportion of children with peanut allergy doubled in these countries over the period from 1998 to 2003. In contrast, peanuts are commonly consumed by infants in relatively high amounts in Africa, Southeast Asia and Israel, yet the rate of peanut allergy is quite low and does not appear to be increasing. Peanut consumption by infants in these parts of the world may actually protect children from developing peanut allergy by promoting oral tolerance to peanuts.

Participants in this study will be randomly assigned to either follow a peanut consumption regimen or a strict peanut avoidance regimen. Those assigned to the peanut consumption group will be asked to consume an age-appropriate snack three times a week for the duration of the study and will be monitored closely during their first introduction to peanut.

Those assigned to the peanut avoidance group will be asked to avoid ingestion of peanut for the first three years of life. A physical exam, allergy testing, and other immune system tests requiring blood collection will occur at Years 1, 3, and 5 following study entry. During the study, parents will maintain regular contact with study dietitians.

• Peanut Allergy
• Eczema
• Egg Allergy
• Food Allergy

• Dietary Supplement: Age appropriate peanut snack
  children are to consume 2 g of peanut protein in three servings per week (total of 6 g) over 3 servings.
  Other Name: Bamba
• Behavioral: Peanut avoidance
  avoidance of peanut as per UK public health recommendations

• Experimental: 1
  Peanut Consumption Group
  Intervention: Dietary Supplement: Age appropriate peanut snack
• Active Comparator: 2
  Peanut Avoidance Group
  Intervention: Behavioral: Peanut avoidance

• Fleischer DM, Conover-Walker MK, Christie L, Burks AW, Wood RA. Peanut allergy: recurrence and its management. J Allergy Clin Immunol. 2004 Nov;114(5):1195-201.
• Palmer K, Burks W. Current developments in peanut allergy. Curr Opin Allergy Clin Immunol. 2006 Jun;6(3):202-6.

Inclusion Criteria:

• Allergy to eggs and/or severe eczema
• Live within traveling distance to London, England, United Kingdom

Exclusion Criteria:

• Clinically significant chronic illness. Participants with eczema or recurrent wheeze are not excluded.
• Positive skin prick test for peanut allergen with a wheel diameter greater than 4 mm in the presence of a negative saline control
• Previous or current consumption of peanut
• Previous allergic reaction to peanut
• Has sibling or primary caregiver who is allergic to peanut
• Certain other immunologic criteria