Study says cathelicidin and SCTE are potential causes of Rosacea

Kevin Berman MD Health Guide November 14, 2007
  • Hi everyone. Today, we are going to deviate a bit from our usual discussion regarding skin cancer and talk about some new and exciting research regarding rosacea. Rosacea is a very common skin condition, usually affecting people with fair skin. The hallmark of rosacea is the "rosey cheek" appearance wherein people look as if they have just finished exercising, or like they are blushing from embarrassment. The red cheek and red nose appearance has given rosacea patients the stigma of looking like the town drunk! And though alcohol can aggravate an already existing case of rosacea, in many cases rosacea is hereditary and it's the nature of the individual's skin that makes it appear red.

     

    There are several stages of rosacea. The first stage is the red cheek appearance, in which the blood vessels on the face become dilated, giving the skin its red appearance. The second stage is when patients get pimple-like lesions. For this reason, rosacea is also known as "acne rosacea" or adult acne. The third stage of rosacea results in "telangectasias", a condition where fine red lines (spider veins), which are permanently dilated blood vessels, appear on the skin. The only way to get rid of these vessels is to have them lasered. The final stage of rosacea, which is fortunately not very common, usually results in a grossly enlarged and disfigured nose.

     

    The majority of people with rosacea are caucasian and notice that they get a "red face" easily in response to certain foods (spicy foods) or drinks (alcohol or caffeinated drinks). Most people leave their rosacea untreated until the acne-like lesions begin to appear. The mainstays of treatment are several creams containing metronidazole or azeleic acid. Often, we use oral antibiotics in the tetracycline family for more severe cases. It is also important for the patient to eliminate behaviors that exacerbate their condition, such as red wine or spicy foods for many. Of coures, life is a balance and it may not be possible to modify one's life in enough ways to minimize rosacea.

     

    This leads us to the question: what causes rosacea and why do certain foods make it worse? We know that there is inflammation of the skin but what leads to this inflammation is unclear. One idea is that abnormal blood vessels of the face become dilated very easily and this leads to the redness. Another idea is that a mite called "demodex" that lives in the hair follicle is the cause of rosacea. In the past week, some exciting research suggests that people with rosacea produce too much of two specific protetins called SCTE and cathelicidin. SCTE is a protein that modifies cathelicidin into a form more likely to lead to rosacea. Cathelicidin is a protein known for its role in protecting the skin from infection. It has, in the past, been linked to atopic dermatitis (eczema) in which these individuals are lacking the protein. This is the first time it has been linked to rosacea, which may result from excess amounts of the protein as stated previously.

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    There are no current treatments that specifically target cathelicidin or SCTE but this most recent discovery may allow scientists to design molecules that block cathelicidin. Most likely, any treatment would be directed towards binding cathelicidin. Any attempt to eliminate excess amounts of it will be difficult to accomplish. For now, continue to use topical creams, oral antibiotics, and behavior modification as these currently offer the best results. Laser treatments can very effectively help the dilated blood vessels. Hopefully, new treatments that target cathelicidin will emerge in the near future. Perhaps other proteins will be identified that play a role in rosacea. Rosacea may not ever be cured, but more research and discoveries will lead to new treatments that can effectively control the disease.