The same biochemical process that causes people to flush when alarmed or embarrassed may be linked to the development of rosacea, according to findings presented by Dr. Richard Granstein, chairman of dermatology at Cornell University, during the recent Society for Investigative Dermatology annual meeting.
"By exploring the potential inflammatory pathways associated with common triggers of rosacea signs and symptoms, we hope to increase our biological understanding of what causes the disorder and how it progresses," Dr. Granstein said. "Such knowledge can then provide a basis for developing improvements in its treatment and control."
In research funded by the National Rosacea Society, Dr. Granstein and colleagues found that emotional stress, a common rosacea trigger, may activate the sympathetic nervous system with the release of adenosine triphosphate (ATP) from sympathetic nerves running throughout the skin's blood vessels. In turn, the researchers discovered that ATP can induce a cascade of biochemical events within the body that may play a role in the inflammation of subtype 2 (papulopustular) rosacea.1
"ATP may act as a messenger within the nervous system to regulate blood flow to the skin by signaling the dilation of blood vessels after exposure to various rosacea triggers, such as emotional stress," Dr. Granstein said.
He noted that flushing may ultimately be prompted by the nerves surrounding the blood vessels of the skin. These dermal vessels are associated with nerves containing substances such as the calcitonin gene-related peptide (CGRP), which dilate the vessels and thus may be associated with facial redness and the growth of the tiny blood vessels called telangiectasia, both signs of subtype 1 (erythematotelangiectatic) rosacea.
Upon investigating the potential significance of CGRP in prompting subtype 1 signs and symptoms, the researchers found that CGRP may play the opposite role in inflammation -- the bumps and pimples characteristic of subtype 2 rosacea. In recent tests, Dr. Granstein and colleagues observed that CGRP inhibits the stimulated release of certain chemokines (small proteins that recruit inflammatory cells) from the cells lining skin blood vessels.
These results suggest that while the nerves containing CGRP may be linked to flushing, they may also serve to regulate inflammation by modulating chemokine production by the cells lining the blood vessels.
"Although there is still much work to be done to fully examine and define this complex process, substances that block or enhance the individual components of such pathways may ultimately lead to the effective control or prevention of rosacea," Dr. Granstein said.
- Seiffert K, Ding W, Wagner JA, Granstein RD. ATPγS enhances the production of inflammatory mediators by a human dermal endothelial cell line via purinergic receptor signaling. Journal of Investigative Dermatology. 2006;126:1017-1027.