Everything You Need to Know About Rosacea
Rosacea is a common inflammatory skin disease that can cause facial redness. It usually affects people with fair skin, generally females, and usually doesn't manifest until adulthood, around the ages of 30-50. It usually affects people with weak immune systems. Rosacea is a chronic condition that gets worse over time and is generally cyclic, flaring up for a period of weeks to months, and then subsiding for a time. It affects nearly 14 million Americans, or about 3% of the population.
Anyone who has rosacea knows that it is frustrating, painful, and mentally debilitating. Not to mention the fact that since the true cause of rosacea hasn't been known, current treatments are often not effective.
It can manifest in a variety of ways, and may look slightly different from person to person.
However, rosacea is generally characterized and diagnosed by the following characteristics:
While we know that things like spicy food, heat and alcohol can aggravate rosacea, we never truly knew why rosacea manifested in the first place.
In 2007, a team of researchers determined that it is not one contributing factor, but a combination of two abnormal factors, that actually result in rosacea.
It appears to be the over-production of two inflammatory proteins which results in excessive levels of a third protein that causes rosacea symptoms.
Researchers first observed in the lab that anti-microbial peptides caused the exact same symptoms in the skin that rosacea does, such as redness, an increase in visible blood vessels, bumps or pimples. The peptides also reacted to the same triggers (spicy food, heat, alcohol, etc).
When they looked at patients with the disease, every one of them had far more peptides than normal.
To learn why these patients have abnormal peptides, the researchers examined the source of these molecules. The precursor form of these peptides, called cathelicidin, is normally known for its function to protect the skin against infection. In other skin diseases, a deficiency of cathelicidin correlates with increased infection. In rosacea patients, researchers found the opposite was true; too much cathelicidin was present in their skin. They also observed that it was a different form of cathelicidin than found in people without the skin disorder.
Patients with rosacea also had greatly elevated levels of enzymes called stratum corneum tryptic enzymes (SCTE). These enzymes turned the precursor into the disease-causing peptide.
By injecting the cathelicidin peptides found in rosacea, or adding SCTE, they were able to increase inflammation, proving that these abnormalities can cause the disease.
Thus, it is too much SCTE and too much cathelicidin that leads to the abnormal peptides that cause the symptoms of this disease.
But wait, a 2012 study showed that rosacea may actually be triggered by bacteria that live within tiny mites that reside in the skin.
The mite species Demodex folliculorum usually lives harmlessly inside the pilosebaceous unit which surrounds hair follicles of the face. They are normal inhabitants of the face and tend to increase in number with age and skin damage (following sunlight, or damage caused by products). The mites eat sebum, or facial oil, and colonise your face at puberty.
The numbers of Demodex mites living in the skin of rosacea patients is found to be higher than in normal individuals, which has previously suggested a possible role for the mites in initiating the condition. More recently, the bacterium Bacillus oleronius was isolated from inside a Demodex mite and was found to produce molecules provoking an immune reaction in rosacea patients. Other studies have shown patients with varying types of rosacea react to the molecules produced by this bacterium -- exposing it as a likely trigger for the condition. What's more, this bacterium is sensitive to the antibiotics used to treat rosacea.
The bacteria actually live in the digestive tracts of Demodex mites found on the face, in a mutually beneficial relationship. When the mites die, the bacteria are released and leak into surrounding skin tissues -- triggering tissue degradation and inflammation. Once the number of mites increase, so does the number of bacteria, making rosacea more likely to occur. Targeting these bacteria may be a useful way of treating and preventing this condition.
Healthy adults have around one or two mites per square centimetre of facial skin. People with rosacea, however, can have 10 times as many
However it is possible that the presence of lots of mites may be a result of the underlying issue, not the cause of rosacea.
So, what does this mean for treatment? Clearly rosacea is a sinister little condition. Well, antibiotics are most often prescribed, and tend to alleviate the symptoms of rosacea temporarily in patients because some of the antibiotics work to inhibit these enzymes. However, this isn't a sufficient long-term treatment option (and may lead to more serious conditions like bacterial resistance to antibiotics, as well as auto-immune diseases and gastrointestinal disorders). Bacteria are not the right target, afterall.
Unfortunately, these findings are still very preliminary and thus, I am sorry to report that a better treatment option has not yet been developed. The cure for rosacea remains elusive, and all currently used medications are for symptomatic control only. No precise treatment has become the standard of care; treatment remains empirical. It seems the best options, at this time, are topical azelaic acid or metronidazole. New light treatments seem to be effective, also, but can be quite expensive. This, coupled with avoiding aggravating "triggers" like spicy food, heat and alcohol, can help avoid flare-ups.