Abstract

Rosacea is a chronic inflammatory cutaneous condition, characterized by facial redness in the first stages, followed by papules, pustules and deformities later on the course. The pathogenesis of the disease involves several factors, such as immunologic, infectious and environmental triggers. Genetic predisposing factors are also postulated due to the remarkably positive family history often found. Through a detailed literature review, we aim to qualify and quantify the impact of climatic versus genetic factors on rosacea epidemiology worldwide. Possible associations are here considered, including the higher prevalence of rosacea in fair-skinned individuals of Northern European descent, the influence of the latitude, cold weather, and the diagnostic inaccuracy in people with skin of color. Further, we discuss the roles of cold-induced vasodilation, the skin colonization by Demodex mites, and the findings from the most recent genetic studies in this field.