Question

• Will infants who are exposed to peanuts in-utero and throughout breastfeeding be at increased risk of atopy in the future?

Clinical Bottom Lines

1. Peanut allergy in children is not associated with maternal ingestion of peanuts while pregnant and breastfeeding.¹
2. Peanut allergy is associated with consumption of soy milk/formula, rashes over joints and in skin creases, and oozing, crusted rash.
3. Possibly, inflamed skin exposed to peanut-oil preparations can cause allergic sensitization.

Summary of Key Evidence

1. Data were obtained from the Avon Longitudinal Study of Parents and Children of 14,000 children from SW England whose expected date of delivery was between 1991-1992. Questionnaires were given at 1, 6, 15, 18 mos of age and every 6 mos thereafter.¹
2. Forty-nine children who were found to be exposed to peanuts by the questionnaire were interviewed. Thirty-six had skin testing for peanut allergy, with 29 found to be positive. Twenty-three of the peanut allergic children had a food challenge.
3. Control groups included children without a peanut exposure and a group of infants diagnosed with eczema at <6 mos whose mothers also had a history of eczema.
4. There appears to be an association between peanut allergy and:
   Consumption of soy milk (adjusted OR 2.61)
   Rash over joints and skin creases (adjusted OR 2.60)
   Oozing, crusted rash (adjusted OR 5.22)
   Use of peanut-oil preparations (adjusted OR 7.49).
   

Additional Comments

• The lack of association between peanut consumption and allergy could be due to the immunologic concept of tolerance. Presentation of antigens to the thymus and the GI tract has been found to promote tolerance.
• Allergic sensitization may occur through the dermatologic route:
  -antigen exposure via peanut-oil containing skin products
  -immunomodulation from steroid cream use
• This study brings up significant safety issues and future consequences in exposing children to possible anaphylactic reactions!

Citation

1. Lack G, Fox D, Northstone K, Golding J; Avon Longitudinal Study of Parents and Children Study Team. Factors associated with the development of peanut alergy in childhood. N Engl J Med 2003;348: 977-85.
2. Fox DE, Lack G. Peanut allergy. Lancet 1998;352: 741-2.

CAT Author: Christina M. Lindell, MD

CAT Appraisers: Alex J. Kemper, MD

Date appraised: November 3, 2004