Published online: December 14, 2017
Recent reports from the US and UK suggest that the prevalence of food sensitization (where an individual’s immune system recognizes some foods as allergens even if that person is not allergic) in the general population of older children has not changed over the last 2 decades, which is surprising considering the apparent increase in food allergy reported from multiple sources. However this question has not been addressed for infants when the prevalence of food allergy is at its highest, or for infants at high risk of food allergy when their parents or siblings also have allergic disease. Australia, which has the highest reported prevalence of food allergy internationally, is the ideal location to address this question.
Recently, in The Journal of Allergy and Clinical Immunology: In Practice, Peters et al compared the prevalence of food sensitisation from two cohorts of infants in Melbourne, Australia, recruited 15 years apart. Their study included 620 high-risk infants with a family history of allergy from the Melbourne Atopy Cohort Study born 1991-1994, and a subgroup of high-risk infants from the population-based HealthNuts study (n = 3,661/ 5,276), born 2006-2010. Participants in both studies had skin prick testing for peanut, egg, and milk when they were 12-months-of-age. A statistical procedure called standardization was used to generate adjusted prevalences of food sensitization that could be used in a like-for-like comparison between the cohorts.
This study found that the prevalence of food sensitization appears to have remained stable between 1991-1994 and 2007-2011 for infants at high risk of food allergy. This finding is surprising given that anaphylaxis hospital admission rates have increased markedly over this same period. The article discusses possible reasons for this apparent discrepancy. Given that food sensitisation has not changed, the reported increase in food allergy could be due to an increase in the proportion of high-risk infants within the population, an increase in food allergy in low-risk infants, or changes in the relationship between food sensitization and food allergy. An alternative explanation is that food allergy may not be on the rise and any apparent increase is due to earlier under-reporting, increased awareness or severity of reactions, particularly anaphylaxis.
The Journal of Allergy and Clinical Immunology: In Practice is an official journal of the AAAAI, focusing on practical information for the practicing clinician.