Smoking, an exacerbating factor for rosacea?

In a study conducted by Wen-Qing LI in 2017 on 95,809 women, researchers sought to verify a possible association between rosacea and smoking. Compared to never having smoked, researchers observed an increased risk of rosacea associated with previous smoking (risk ratio = 1.09), but a reduced risk associated with current smoking (risk ratio = 0.65). These results therefore suggest that current smokers had a reduced risk of rosacea, but former smokers had a higher risk. Furthermore, an increase in the number of packs smoked per year of smoking was associated with a decrease in the risk of rosacea among current smokers and an increase in risk among former smokers.

Other studies align with these findings, however, some confusion remains. Indeed, Chen-Yi WU and his colleagues noted, in an experiment involving 59,973 participants, a significant reduction in the risk of rosacea among current smokers. However, no significant association was observed between former smoking and the risk of rosacea, revealing inconsistencies among the studies. Furthermore, the validity of the results from the study conducted by LI was limited by self-reported rosacea diagnosis and by uncontrolled confounding factors, particularly comorbidities.

Although the mechanisms underlying the reduced risk of rosacea in current smokers have not yet been elucidated, several hypotheses are being considered. Studies have found a higher prevalence of erythematotelangiectatic rosacea in active smokers, the pathogenesis of which involves vasodilation. The nicotine contained in tobacco can cause a microvascular contraction, which could reduce the vasodilation associated with rosacea. Furthermore, its anti-inflammatory effects could mitigate inflammation in the case of rosacea.

However, the angiogenic effects of nicotine could also induce the development of the disease. Moreover, cigarette smoke could accelerate the degradation of collagen and elastic fibers, which could damage the skin barrier. Thus, according to these hypotheses, the reduced risk of rosacea in current smokers could be temporary and the observation of an increased risk of rosacea in former smokers becomes more consistent.

Given the confusion of scientific data, it is challenging to take a stance. More studies on this subject are currently underway.