Abstract
Scalp seborrheic dermatitis, or dandruff, is thought to worsen during the winter when there is later sunrise and less daylight. This study investigates trends in search engine interest for the term "dandruff" as they relate to changes in daylight, sunrise, and seasonality. We investigated the search interest in several countries of varying latitudes over a five-year period, and we explore the effect of daylight saving time on disease interest within two cities in the United States. We discuss our findings in the context of hormonal changes and skincare/behavior.