Early-Life Respiratory Infections Linked to Higher Risk of Childhood Atopic Dermatitis
Key Takeaways
- A large cohort study found that a higher burden of respiratory infections during the first 3 years of life was associated with an increased risk of developing atopic dermatitis (AD) through childhood.
- The association demonstrated a dose-dependent relationship and was replicated in 2 independent birth cohorts from Denmark and the US.
- The findings persisted after adjustment for filaggrin (FLG) variants and systemic antibiotic use.
Children who experience a greater burden of respiratory infections during the first 3 years of life may face an increased risk of developing atopic dermatitis (AD), according to new research in JAMA Dermatology.
Investigators analyzed data from 2 independent birth cohorts (the Danish Copenhagen Prospective Studies on Asthma in Childhood (COPSAC2010) and the US Vitamin D Antenatal Asthma Reduction Trial [VDAART])to evaluate whether early-life infections influence AD development through childhood. The primary analysis included 663 children from COPSAC2010, where investigators tracked physician-documented infections, AD diagnoses, SCORAD scores, antibiotic use, and filaggrin (FLG) gene status from birth through age 10 years.
Respiratory Infection Burden Shows Dose-Dependent Association With AD Risk
Children in the highest tertile of infection episodes had a 61% higher likelihood of developing AD than those in the lowest tertile (adjusted odds ratio [AOR], 1.61; 95% CI, 1.05-2.47; P = 0.03). Similarly, children with the greatest number of infection days had a 69% higher risk (AOR, 1.69; 95% CI, 1.11-2.58; P = 0.01).
Each additional infection episode was associated with an incremental increase in AD risk, independent of systemic antibiotic exposure and FLG genetic variants. The association was driven primarily by respiratory infections rather than gastrointestinal illnesses or other infection types.
The findings were independently replicated in the VDAART cohort of 707 US children. Those in the highest tertile of infection episodes had a 76% greater likelihood of physician-diagnosed AD through age 6 years compared with children in the lowest tertile (OR, 1.76; 95% CI, 1.16-2.70; P = 0.01). Each additional infection episode was likewise associated with a modest but statistically significant increase in AD risk (OR, 1.03; 95% CI, 1.01-1.05; P = 0.002).
Study limitations include the observational design, which precludes establishing causality, and differences in AD ascertainment between the Danish and US cohorts.
"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," the authors wrote.
Source
Brustad N, et al. JAMA Dermatology. Doi:10.1001/jamadermatol.2026.2626