Research suggests that people with rosacea may have a genetic susceptibility to developing the condition and that environmental factors, in particular the microbiome, also play a role. Most importantly, however, there is mounting evidence that rosacea might be an outcome of systemic inflammation1
There is a small but significant association between systemic inflammatory diseases, some of which can be potentially serious, and rosacea. The greatest evidence is for links between rosacea and cardiovascular disease and inflammatory bowel disease, but there are also less strongly validated links with certain neurological diseases, in particular parkinsonism, but also dementia and Alzheimer’s.
A greater understanding of rosacea’s shared etiology will not only aid diagnosis and treatment for patients with rosacea, it could have wider clinical implications. If rosacea is shown to have high predictive value for the development of particular systemic disorders, it could provide a valuable early warning sign for these conditions, says Richard L. Gallo M.D., Ph.D., Irma Gigli Endowed Chair, Distinguished Professor and Founding Chairman, Department of Dermatology, University of California, San Diego.
“We are getting increasing evidence that some of the inflammatory mediators that are released in the skin of rosacea patients and psoriasis patients as well can act systemically so something that is produced in the skin may circulate around and act on vessels of the heart or the lumen of the gut,” he says. For example, there is now evidence implicating TH1 and TH17 cytokines and B cells in rosacea.2
Unfortunately, Gallo adds, “A biochemical marker that would distinguish the inflammation of rosacea from other types of inflammation has not been clearly identified.”
A biochemical identifier unique to rosacea would enable dermatologists to easily confirm suspected diagnosis and monitor disease progression, and researchers to assess the potential of new candidate therapies.
Other than improvements in therapy this would be the most useful step forward that could be made in our knowledge of the condition, he says.
1. Gallo RL, Granstein RD, Kang S, Mannis M, Steinhoff M, Tan J, Thiboutot D.Rosacea comorbidities and future research: The 2017 update by the National Rosacea Society Expert Committee. J Am Acad Dermatol. 2017 http://dx.doi.org/10.1016/j.jaad.2017.06.150
2. Buhl T, Sulk M, Nowak P, et al. Molecular and morphological characterization of inflammatory infiltrate in rosacea reveals activation of Th1/Th17 pathways. J Invest Dermatol. 2015;135: 2198-2208.