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Seasonality and global public interest in psoriasis: an infodemiology study
  1. Qian Wu1,
  2. Zhiwei Xu2,
  3. Yi-Lin Dan1,
  4. Chan-Na Zhao1,
  5. Yan-Mei Mao1,
  6. Li-Na Liu1,
  7. Hai-Feng Pan1
  1. 1 Epidemiology and Biostatistics, School of Public Health, Anhui Medical University, Hefei, China
  2. 2 School of Public Health and Social Work and Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia
  1. Correspondence to Hai-Feng Pan, Epidemiology and Biostatistics, School of Public Health, Anhui Medical University, Hefei, Anhui, China; panhaifeng1982{at}


Objective Although patients with psoriasis frequently report seasonal changes in their symptoms, the seasonality of psoriasis has rarely been explored. This study aims to investigate the seasonal pattern of and global public interest in psoriasis using Google search data.

Methods Internet search data were collected from Google Trends. Data on the relative search volume (RSV) from January 2004 to December 2018 were retrieved using the term psoriasis. Cosinor analyses were conducted to examine the seasonality of psoriasis using data from two southern hemisphere countries (Australia and New Zealand) and four northern hemisphere countries (USA, Canada, UK and Ireland).

Results Overall, searches for psoriasis steadily decreased between 2004 and 2010, and then rose from 2011 to 2018. On cosinor analyses, RSV of ‘psoriasis’ displayed a significant seasonal variation worldwide (p<0.025). Further analyses confirmed the seasonality of psoriasis-related RSV in Australia, New Zealand, USA, Canada, UK and Ireland (p<0.025 for all), with peaks in the late winter/early spring months and troughs in the late summer/early autumn months. The top 11 rising topics were calcipotriol/betamethasone dipropionate, ustekinumab, apremilast, shampoo, eczema, guttate psoriasis, seborrhoeic dermatitis, dermatitis, psoriatic arthritis, atopic dermatitis and arthritis.

Conclusion There was a significant seasonal pattern for psoriasis, with peaks in the late winter/early spring and troughs in the late summer/early autumn. Further studies are warranted to confirm the seasonal pattern of psoriasis using clinical data and to explore the underlying mechanisms.

  • google trends
  • global public interest
  • seasonality
  • psoriasis
  • public health

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  • QW and ZX are co-first authors.

  • Contributors QW, ZX and H-FP designed the study. QW contributed to Google searches and data analyses. QW and ZX drafted the manuscript. Y-LD, C-NZ, Y-MM and L-NL contributed to manuscript revision. All the authors approved the final submitted version.

  • Funding This work was supported by the National Natural Science Foundation of China (grant numbers 81872687 and 81573222).

  • Competing interests None declared.

  • Patient consent for publication Not required.

  • Ethics approval This research was approved by the Ethics Committee of Anhui Medical University.

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Data availability statement Data are available upon reasonable request.