Clinical Edge

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Seasonal Patterns Established in Psoriasis

There is a significant seasonal pattern for psoriasis, a new study found. Using Google search data, researchers investigated the seasonal pattern of and global public interest in psoriasis. Data on the relative search volume (RSV) from January 2004 to December 2018 were retrieved using the term psoriasis. Among the highlights:

  • Peaks came in late winter/early spring and troughs in the late summer/early autumn.
  • Analyses confirmed the seasonality of psoriasis-related RSV in Australia, New Zealand, US, Canada, UK, and Ireland.
  • The top rising topics were calcipotriol/betamethasone dipropionate, ustekinumab, apremilast, shampoo, eczema, guttate psoriasis, seborrheic dermatitis, dermatitis, psoriatic arthritis, atopic dermatitis, and arthritis.


Wu Q, et al. Seasonality and global public interest in psoriasis: an infodemiology study. [Published online ahead of print September 11, 2019]. Postgrad Med J. doi: 10.1136/postgradmedj-2019-136766.


This report highlights searches on the internet for psoriasis based on seasonal times of the year. It is a well-accepted phenomenon that psoriasis tends to worsen during the winter months and may improve or be stable during the summer months based on the amount of sun during these seasons. In fact, some of the data for clinical trials in psoriasis may be influenced and confounded by seasonal changes. There seems to be a correlation between the stability or instability of psoriasis during different times of the year and searching for various topics on the internet for psoriasis. —Paul S. Yamauchi, MD, PhD; Clinical Assistant Professor of Dermatology David Geffen School of Medicine at UCLA; Harbor-UCLA Medical Center Division of Dermatology; Adjunct Associate Professor John Wayne Cancer Institute.