Infant emollient use increases pollen sensitization via skin barrier dysfunction
Published online April 7, 2025
Pollen allergy often starts in early life. Allergic symptoms often result from cross-reactivity between specific pollen allergens and similar structured proteins in plant-based foods. Given the different exposure routes, via skin and oral via food intake, this study evaluated whether early-life interventions of food introduction and skin emollient use could prevent birch and grass pollen sensitization by age three.
The study by S. Wärnberg Gerdin et al., recently published in The Journal of Allergy and Clinical Immunology: In Practice, is based on the Preventing Atopic Dermatitis and Allergy in Children (PreventADALL) study, a population-based randomized controlled trial conducted in Norway and Sweden. A total of 2394 newborns were randomized (1:1:1:1) to: (1) control group, (2) skin emollient care (oil baths and facial cream from 2 weeks to 9 months), (3) early food introduction (peanut, cow’s milk, wheat, and egg from 3 to 6 months), or (4) combined interventions. Parents were instructed to apply interventions 4–7 times per week.
Allergic sensitization to birch and grass (timothy) was assessed by skin prick tests and specific IgE analyses at multiple time points from 6 months to 3 years. A mediator analysis evaluated the effect of skin intervention on skin barrier function by transepidermial waterloss (TEWL) measured at 3 months.
At age 3 years, 7.8% of children were sensitized to birch and 2.7% to grass, with no significant differences related to the food intervention. Higher TEWL in infancy was observed among children sensitized to pollen, particularly among those randomised to skin intervention. Regular skin emollient use was significantly associated with increased sensitization to birch, but not to grass. Mediator analysis indicated a significant indirect effect of emollient use on pollen sensitization through increased TEWL at 3 months, although neither a direct nor total effect was found.
Our findings suggest that early food introduction did not affect sensitization to birch or grass pollen in young children, while regular skin emollient care in early infancy may increase the risk of pollen allergy via impairment of the skin barrier. This highlights the importance of cautious skin care practices in early life and the potential need to reconsider universal emollient recommendations in infancy. Future studies should investigate the mechanisms linking skin emollient use in infancy to impaired barrier function and increased allergy risk.
The Journal of Allergy and Clinical Immunology: In Practice is an official journal of the AAAAI, focusing on practical information for the practicing clinician.
Full Article