The understanding of the impact of exposure to microbes in the first weeks and months of life has grown over the course of the past decade and this includes the effects it has on the development of the immune system as well as determining the susceptibility to having a food allergy. A report in The Journal of Allergy and Clinical Immunology examines the role that pacifier use as well as the sanitization method for the pacifier in the first year of life has on the risk of food allergy.1
The investigators used a birth cohort that recruited pregnant women at less than 28 weeks’ gestation who lived in southeast Australia. The families received follow-up when the infant reached his or her first birthday. Infants were not included in the study if they had been born before 32 weeks’ gestation or had a major congenital malformation, genetic disease, or serious illness. There were also questionnaires, collected at study enrollment and 1, 6, and 12 months of age, that asked about pacifier use as well as pacifier sanitization. Sanitization options included giving the pacifier back to the baby without washing; putting the pacifier in the parent’s mouth before giving back to baby; washing it under tap water; washing in boiling water; and washing or sterilizing with antiseptic agent. Challenge-assessed food allergies were reviewed at 12 months.
Among the 894 families included in the study, the investigators found that any pacifier use at 6 months was linked to food allergy (adjusted odds ratio, 1.94; 95% CI, 1.04-3.61), but not with use at other ages. The link was driven by joint exposure of pacifier-antiseptic use (adjusted odds ratio, 4.83; 95% CI, 1.10-21.18), when compared to no pacifier use. The use of pacifiers without sanitizing with antiseptic at 6 months was not linked to food allergy. Overall, antiseptic use was linked to food allergy (adjusted odds ratio, 3.56; 95% CI, 1.18-10.77) when compared to no antiseptic use. Additionally, the persistent and repeated use of antiseptic agents during the first 6 months was linked to higher food allergy risk (P = .029).
The investigators concluded that pacifier use and antiseptic cleaning appeared to be linked to a higher risk of food allergy. They urged future research to examine the biological pathways that lead to this link.
1. Soriano V, Koplin J, Forrester M et al. Infant pacifier sanitization and risk of challenge-proven food allergy: A cohort study. Journal of Allergy and Clinical Immunology. 2021;147(5):1823-1829.e11. doi:10.1016/j.jaci.2021.01.032