Allergenic Food Introduction Largely Completed During COVID-19 Lockdown

Naomi McCallion, PhD

A new investigation found that despite social isolation caused by the COVID-19 pandemic, allergenic food introduction was largely completed at 12 months by families with children born during lockdown.

The study was presented at the American Academy of Allergy, Asthma & Immunology Annual Meeting (AAAAI) 2022.

Additionally, atopic dermatitis and sensitization to eggs were more common in the study’s cohort during what they called the “COVID-19 era cohort”.

The CORAL study was a longitudinal study that examined the impact of the pandemic on allergic and autoimmune dysregulation of 365 infants who were born in Ireland during the first lockdown of March-May 2020.

Investigators led by Marguerite Lawler, PhD, Royal College of Surgeons, Dublin, hypothesized that social and physical changes as a result of the lockdown could have consequences for microbiome diversity and allergic sensitization.

The Methods

Lawlaer and colleagues issues questionnaires to families willing to participate in the study, which were completed at 6 and 12 months.

At the 12-month review, skin prick testing, COVID-19 antibody testing and SCORAD assessment of atopic dermatitis were performed. Additionally, rates of allergen sensitization were compared with national data from a previous study, BASELINE, from 2008-2011.

The Findings

Between 6 and 12 months, investigators observed that the introduction of allergenic foods increased from 46% to 99% for cow’s milk, 25.7% to 98.5% for eggs, and 12.4% to 78.2% for peanuts.

Additionally, 5.8% (20/344) of CORAL infants were sensitized to egg compared to 3.18% (45/1540) in BASELINE (p 50.007), though rates of milk and peanut sensitization and doctor diagnosed food allergy rates were similar between cohorts.

However, the cumulative incidence of atopic dermatitis at 12 months increased in the CORAL group to 87/ 344 (25.3%) compared to 232/1494 (15.5%) in BASELINE ( p<0.0001).

“Atopic dermatitis and sensitization to egg appear to be more common in this COVID-19 era cohort at 12 months,” the team wrote. “Whether this represents a long-term trend over 10 years or short-term changes due to COVID-19 mandated social isolation remains to be determined.”