Allergic diseases in infancy: I - Epidemiology and current interpretation

World Allergy Organ J. 2021 Nov 12;14(11):100591. doi: 10.1016/j.waojou.2021.100591. eCollection 2021 Nov.

Abstract

Objective: Among non-communicable diseases, the prevalence of allergic diseases has increased significantly in the new millennium. The increase of allergic diseases is linked to the changing environment of infants.

Methods: This narrative review summarizes the discussions and conclusions from the 8th Human Milk Workshop. Information from the fields of pediatrics, epidemiology, biology, microbiology, and immunology are summarized to establish a framework describing potential avenues for the prevention of allergic diseases in the future.

Results: Several environmental circumstances are linked to the development of allergic diseases. While cesarean section is increasing the risk of allergies, early childhood exposure to a farm environment has a protective effect. From their analysis, nutritive and non-nutritive factors influencing the allergy risk in later life have been identified. The effect of breastfeeding on food allergy development is non-univocal. Human milk components including immunoglobulins, cytokines, and prebiotics have been indicated as important for allergy prevention.

Conclusion: Many factors linked to the western lifestyle have been associated with the development of allergic diseases. This suggests several theories that may serve as a basis for new protective interventions. While it is indubitable that mother's milk protects from infectious diseases, its role in the prevention of allergic diseases is to be elucidated.

Keywords: Allergy; Allergy prevention; Farm effect; Hygiene hypothesis.

Publication types

  • Review