TOPLINE

Children with a high burden of infections through age 3 showed a greater risk of developing atopic dermatitis (AD) in a large Danish cohort study.

METHODOLOGY

• Researchers used data from 663 children in the Danish Copenhagen Prospective Studies on Asthma in Childhood (COPSAC2010) birth cohort, monitored from birth to age 10 years between November 2008 and November 2010.
• Researchers replicated the COPSAC2010 findings in 707 children from the US VDAART cohort followed to age 6 years.
• Parents recorded daily infections including common cold, acute otitis media, tonsillitis, pneumonia, gastroenteritis, and fever in COPSAC2010 through age 3; VDAART monitored cold, respiratory infection, otitis media, and fever.
• The primary outcomes were AD diagnosis through age 10 years in COPSAC2010 and physician-diagnosed AD through age 6 years in VDAART.

TAKEAWAY

• In the Danish cohort, children with more infection episodes (upper vs lower tertile: adjusted odds ratio [AOR], 1.63; P = .02) and infection days (upper vs lower tertile: AOR, 1.80; P < .001) had an increased risk for AD.
• Each additional infection episode was associated with a modest increase in the risk for AD (AOR, 1.02; P = .03), demonstrating a dose-response relationship.
• Respiratory infection subtypes and otitis media were strongly linked to an AD diagnosis: upper vs lower tertiles for common colds (AOR, 1.71; P = .01), tonsillitis (AOR, 1.61; P = .03), pneumonia (AOR, 1.73; P = .01), and acute otitis media (AOR, 1.98; P = .002).
• In the US cohort, children in the upper vs lower infection episode tertile had an increased risk for AD (odds ratio [OR], 1.76; P = .01), and each infection episode raised the odds (OR, 1.03; P = .002).

IN PRACTICE

“Early common infection burden, and in particular upper respiratory infections, were associated with AD in childhood,” the authors of the study wrote. “These findings suggest a long-term relationship between early respiratory infections and AD that has previously been unclear due to inconsistent findings in previous studies,” they added.

SOURCE

The study was led by Nicklas Brustad, MD, PhD, Herlev and Gentofte Hospital, University of Copenhagen, Copenhagen, Denmark, and was published online on July 29 in JAMA Dermatology.

LIMITATIONS

The limitations included the observational study design, a modest sample size that limited conclusions about temporal associations between infections and AD, and the lack of adjustment for antibiotic exposure.

DISCLOSURES

The study was funded by the Independent Research Fund Denmark and the LEO Foundation. Three authors disclosed receiving personal fees, speaker fees, grants, and advisory fees from ALK, Thermo Fisher Scientific, Stallergenes Greer, LEO Foundation, TruDiagnostic, Toto, Calico, and Antipode. One author disclosed a pending patent.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.