T07001: The prevalence and natural history of peanut allergy and the investigation into its genetic environment and immunological determinants
Monday 4 November 2002
This research project aims to investigate the prevalence of peanut allergy in UK children and the factors affecting the development of peanut allergy.
Study Duration: December 1995 to May 2003
Contractor: St Mary’s Hospital, London
In order to understand peanut allergy, a number of fundamental questions must be answered:
What is the current prevalence of peanut allergy in UK children?
Which environmental factors influence the development of peanut allergy, and do these factors act before or after birth?
What immunological mechanisms are involved in the development of peanut allergy?
This research project aims to address these questions.
The project will involve approximately 14,000 seven-year-old children who have been followed from birth as part of the Avon Longitudinal Study of Pregnancy and Childhood (ALSPAC).
The prevalence of allergy to peanut and tree nuts will be determined by assessing the children�s medical histories and by analysing the results of skin prick tests and double blind placebo controlled food challenges. Umbilical cord blood collected at the birth of the children will be used to investigate whether evidence of sensitisation to peanut was already present at birth.
Computerised records collected at various time-points during the children�s lives will be analysed to identify any environmental factors that may be involved in the development of food allergy.
In order to investigate the immunological mechanisms involved in peanut allergy, the immune responses of children with this condition will be compared with those who are not peanut allergic. This part of the study will involve children from the ALSPAC cohort and also children with peanut allergy who attend the St Mary�s hospital allergy clinic.
Results and findings
This project utilised data resulting from a large cohort study based in the Avon area. The prevalence of peanut and/or tree nut allergies in this cohort was high, affecting almost 2% (i.e. 1 in 50 children). Approximately 40% of children with peanut allergy also reacted to tree nuts. This suggests that children with peanut allergy should avoid tree nuts in their diet as well as peanuts. One third of children who developed peanut allergy had outgrown their peanut allergy before the age of five. This suggests that peanut allergy is not necessarily life-long and that diagnosis should be continually reviewed over time.
Analysis of the infants' umbilical cord blood showed that there was no evidence of peanut allergy at birth, suggesting that peanut allergy develops after birth. This research found no link between maternal consumption of peanuts during pregnancy and breastfeeding and the development of peanut allergy by the children. However, peanut allergy was found to be associated with eczema and rashes in early infancy, particularly where preparations containing peanut oil had been applied to the skin of infants with oozing and crusting rashes. A possible link between consumption of soya formula during infancy and the development of peanut allergy was also identified.
Analysis of the children's immune responses showed that the immune cells of peanut allergic children responded to peanut protein more rapidly than in non-allergic children and that they secreted different types of proteins to that found in non-allergic children. Where children had outgrown their peanut allergy, their immune system had returned to normal.
The final report is available from the FSA Library and Information centre.
To obtain a copy, please contact the Enquiry Desk, Dr Elsie Widdowson Library and Information Services, Food Standards Agency (tel: 020 7276 8181/8182 or email:firstname.lastname@example.org)
Lack G, Fox D, Northstone K, Golding J (2003). Factors associated with the development of peanut allergy in childhood. N Engl J Med, 348; 977-85
Turcanu V, Lack G (2003). Characterisation of lymphocyte responses to peanut in normal children, peanut-allergic children and allergic children who acquired tolerance to peanuts. J Clin Investigation, 111(7):1065-72
Lack G, Northstone K, Golding J (2003). Peanut study. N Engl J Med, 348; 977-85
Lack G, Roberts G. Antigen-specific lymphocyte proliferation and cytokine production differentiate children who have outgrown their peanut allergy. American Academy of Allergy, Asthma and Immunology, Denver, March 2003.
Contact: For any enquiries concerning this research project, please contact the relevant Programme contact or email email@example.com