• Proportion of participants with peanut allergy at 60 months of age [ Time Frame: 60 months ] [ Designated as safety issue: No ]
  

• 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 ]
  

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.