The impact of meteorological factors on the incidence of infantile atopic dermatitis.

Background: The role of the climate regarding atopic dermatitis (AD) in infants is still unclear. This study aimed to determine the relationship between meteorological conditions and the incidence of early AD.

Methods: The study was conducted using a retrospective design. We analyzed children aged 0-24 months with clinically diagnosed AD (n = 603), including infantile eczema (IE, n = 292), in relation to the mean monthly meteorological data in Minsk. The Mantel-Haenszel method was used to study the association between an AD outcome and meteorological variables, stratifying by potential confounders. Seasons of birth were analyzed in children diagnosed with AD before 6 months of age (n = 567) and at 12 months of age (n = 350) from 2005 to 2019.

Results: The incidence rate of IE was negatively associated with air temperature (adjusted incidence rate ratio = 0.75; 95% confidence interval (CI) 0.59-0.94), precipitation (0.74; 95% CI 0.58-0.93), and positively associated with atmospheric pressure (1.31; 95% CI 1.04-1.66). The highest incidence rate of IE was during spring, and the lowest was during summer. Incidences of AD were less frequent among infants born in the spring (18.1% vs. 29.4%, P < 0.001) than among older children. The principal component analysis identified three meteorological combinations where the first one (warm, low humidity) was negatively associated with the incidence rate of AD among children aged 0-24 months (0.77; 95% CI 0.65-0.92), and the third one (rainy, low atmospheric pressure) with IE (0.70; 95% CI 0.54-0.90).

Conclusion: Continental seasonal cold-humid weather may influence early AD incidence. Moreover, short-term meteorological factors may play an important role in the onset of IE.