Aetiology

• The exact aetiology is unknown but the most important climatic exposure is sunlight. There is also evidence that the skin barrier is impaired in people with rosacea. (1)
• Other trigger factors include emotion, windy weather, hot drinks, spicy foods, heavy exertion, alcohol and the incorrect use of topical corticosteroids. These suggest a lack of normal homeostatic control of the blood vessels supplying the pilosebaceous follicle (2)
• General inflammation may be induced by medicines such as amiodarone and nasal corticosteroids, and micro-organisms such as Helicobacter pylori and the Demodex mite (3)
  

Reference:

1. Morgado-Carrasco D, Granger C, Trullas C, et al. Impact of ultraviolet radiation and exposome on rosacea: key role of photoprotection in optimizing treatment. J Cosmet Dermatol. 2021 Nov;20(11):3415-21.

2. Gallo RL, Granstein RD, Kang S, et al. Standard classification and pathophysiology of rosacea: the 2017 update by the National Rosacea Society Expert Committee. J Am Acad Dermatol. 2018 Jan;78(1):148-55.

3. Hoepfner A, Marsela E, Clanner-Engelshofen BM, et al. Rosacea and perioral dermatitis: a single-center retrospective analysis of the clinical presentation of 1032 patients. J Dtsch Dermatol Ges. 2020 Jun;18(6):561-70.