Climate, Humidity, and Population-Level Interest in Dry Skin: Infodemiology Analysis Using Google Trends Across the United States.

Background: Climate and weather factors of temperature and humidity are widely reported to be associated with xerosis (dry skin), a common inflammatory skin condition and frequent driver of pruritus (itchy skin) and reduced quality of life. Growing evidence supports links between environmental conditions and skin barrier function, with extreme climates associated with increased atopic dermatitis-related clinical visits. Mechanistically, temperature and humidity affect the stratum corneum, the skin's primary permeability barrier, with low humidity and high temperature increasing transepidermal water loss and promoting cutaneous inflammation. Objective: This study examines the relationship between climate, namely temperature and humidity, and the general public's experience in dry skin and moisturizing products, throughout the United States. This study sought to address gaps in traditional epidemiologic approaches by linking climate conditions with population-level online search behavior related to dry skin and moisturizer use across the United States. Methods: Publicly available climate data were obtained from the National Oceanic and Atmospheric Administration (NOAA), including average temperature and dew point by state over a recent nine-year period (2016-2025). Dew point served as a proxy for ambient humidity. Google Trends was used to assess relative search interest for five dry skin- and moisturizer-related terms by state during the same period. Search interest was normalized per million residents, and associations between climate variables and search interest were evaluated using linear regression analyses. Statistical analyses were conducted using R. Results: Lower average temperatures and lower dew points were associated with higher dry skin-related search interest, while warmer, more humid states showed lower interest. Both temperature and dew point demonstrated significant negative associations with Google search interest. This work was not funded and data collection was performed using publicly available, free databases. Conclusions: Population-level search behavior related to xerosis reflects national patterns of climate-associated dermatologic burden.