We’ve all been exposed to Demodex Bacteria Proteins ?

Written by on July 15, 2009 in Demodex Mites, What Causes Rosacea? with 11 Comments

An article published today in the Irish Times takes one more step in the direction of showing an association between demodex mites and rosacea. Readers of Rosacea News will know that a lot of research has tried to find a causative link between the presence of demodex mites and rosacea symptoms.

Some progress towards a link between the two was realised when a particular type of bacteria present in demodex, called Bacillus oleronius was isolated. This bacteria was then analysed and 2 resulting proteins were found to be quite interesting. These proteins were shown to induce an increased inflammatory response specifically in rosacea sufferers.

The Irish Times newspaper article quotes Dr. Kevin Kavanagh from NIU Waynooth (who has received NRS funding for demodex research), who says that a survey of 30 patients found 80% had been exposed to large amounts of 2 demodex bacteria proteins. This appears to me to be a new discovery. Immune tests were performed on the patients to show that the patients had been exposed to Bacillus bacterium inside Demodex mites.

We know from previous studies that “two antigenic proteins of size 62 and 83 kDa” isolated in Bacillus oleronius have the potential to stimulate an inflammatory response in patients with papulopustular rosacea. This is the first time I’ve see mention of a high proportion of rosacea sufferers been shown to been exposed to these 2 proteins.

This short article suggests that an immune response to these 2 proteins is a very common occurrence in rosacea sufferers. So common in fact that it warrants further investigation to see what this really means for rosacea diagnosis and treatment. At the least, a blood test to confirm rosacea seems like a real possibility.

Suggesting that eradicating Bacillus oleronius via antibiotics is the reason for their success in treating rosacea does seem a bit of a stretch. Perhaps interrupting how these proteins induce an inflammatory response is another way of understanding how this all fits together.

As this is just a discussion article in a newspaper, it will be useful to see the full article when it is published later this year. My feeling is that we are still only making baby steps along this path of logic. They are steps that seem to be in the right direction, but it sure takes a long time to get there.

From Study finds cause of rosacea, Tuesday, July 14, 2009, CLAIRE O’CONNELL.

BACTERIA ARE to blame for the inflammatory skin condition rosacea, according to a study involving Irish scientists.

Working with the Mater hospital, the researchers previously identified a Bacillus bacterium inside Demodex mites. The bacteria release two proteins that trigger an inflammation in patients with facial rosacea.

Immune tests on 30 patients found that 80 per cent had been exposed to large amounts of the two bacterial proteins, said Dr Kavanagh of the study, which is to be published in Ophthalmology later this year.

“Now that we know it’s primarily probably a bacterial disease, we know the proper way to treat it is with antibiotics at a low level over a long period of time,” Dr Kavanagh said, noting that washing the skin with dilute tea tree oil also killed the bacteria.

“The other implication is that we could do a simple blood test to say whether a patient has rosacea or not. That’s something we will investigate in the future.”

The article also mentions a link between demodex bacteria and ocular rosacea.

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About the Author: David Pascoe started the Rosacea Support Group in October 1998. .

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11 Reader Comments

  1. Linda says:

    I have always had a ruddy complexion but it has never bothered me as badly as in the last 10 yrs (since my husband died – ergo, i related it to stress). I have had a significant hair loss since that time also. The sx would wane and exacerbate depending on what was going on in my life. HOWever, in the last few months this has gotten significantly worse as well as the hair loss. I have also been traveling and thought i could have picked up something somewhere.

    I have seen dermotologists who have been useless stating that “all my skin problems were due to my ‘skin type'”. This was no help and a waste of $$.

    I have always felt that I had a low grade infection (being a former RN, I assumed staph). I say this b/c when I have been on an antibiotic for sinus infections, my face and scalp clear up remarkably and my hair starts to regrow. One dermat. gave me cleocin for my scalp which has definitely helped the scalp breakouts.

    I also have felt that something was “crawling” in my hair, but having very thin, gray hair, I always thought i could see whatever it was. Something microscopic would make sense.

    I cannot get my drs to listen to me and i know i have some semblence of reason to what is going on with me.

    can you help?

  2. Sam says:

    Testing for the Demodex mite is not difficult, but a good microscope is required. Instructions are available at the following URL:


    I used virgin olive oil to dissolve the skin oil and to suspend the mites for observation. You’ll understand after reading the instructions in the article.

    The tea tree oil treatment should be tried first. If that doesn’t clear it up and kill the mites, then perhaps the Chinese approach should be considered. Note that it takes weeks to months to achieve a total cure. Treatment with insecticides should not be considered.

    Also note that the Demodex mite is highly contagious. Even indirect contact (e.g., damp towel, cap, pillow, etc.) with a person who is infected can reintroduce the mite to your skin.

    Good luck to you.

  3. Doug says:

    So which antibiotics are effective against Bacillus oleronius? I have read some are not effective..

  4. According to the paper Mite-related bacterial antigens stimulate inflammatory
    cells in rosacea;

    “Antibiotic sensitivity testing showed that B. oleronius was sensitive to tetracycline, doxycycline and minocycline”.

    So it would appear all of the regular rosacea systemic antibiotic treatments will be effective against B. oleronius

  5. Doug says:

    I emailed Dr kavanagh and he said his team will be putting out a new report on their research early next year (2011). he said he believes his team has figured out how the redness of Rosacea occurs. He also said his team has confirmed this in ocular and type 2 Rosacea but are currently testing the other types as well. This is very exciting news! Maybe we can finally know how Rosacea occurs and then we can hopefully find a way to stop it! He didnt say much but it does sound like the mites are NOT the causitive agent but the bacteria from the mites is…

    I am wondering if we get Rosacea due to a weakened immune system due to whatever reason. For many years we could handle these mites and their bacteria but at some point we cant anymore. Does that mean our immune system stops producing antibodies against the bacteria or not enough? Why do women seem to get Rosacea when they start menopause and their hormones are out of whack? Their immune system gets very weak.

    A lot of people believe our digestive system plays a major role in Rosacea and it would make sense in that our 80% of our immune system is related to our digestive system. Bad digestive system=weakened immune system=Rosacea.

    So maybe to treat Rosacea it will mean :

    1) killing as many mites as possible. possibly oral ivermectin, oral metrondazole, topicals, etc. From what I have read the mites are hard to kill and so we might need an aggressive approach for the first month or so and then continue with a maintenance dose.
    2) fight/kill the bacteria from the mites . antibiotics?
    3) find out what is causing your immune system to be weak and fix it.
    4) do everything possible to strengthen your immune system. exercise, reduce stress, eat right, etc…

    All I know I hope something good comes from their research

  6. Comment via email from Linda:

    “thanks for the update. I have found that there are some things that have helped me immensely:

    1. I’ve stopped using Sulfate based soaps and shampoos. I have totally switched to Johnson & Johnson Baby Shampoo, Baby wash and Baby lotion. This has been a great help – i no longer have the break-outs i once had.

    2. I use St. Ives Green Tea face wash which has also decreased greatly any breakouts.

    3. I stopped using Metro-Gel — this stuff was causing horrible whiteheads on my face which disappeared when i stopped using it.

    4. I still have a mild redness and some spider veins on my cheeks. It would be great to get rid of these.”

  7. Antea says:

    This demodex infestation brought so many unwanted effects. I knew about scabbies as a teen. Now not difficult to get informed online. But I have many questions and would really like to form a group of us researching deeply and even experimenting.
    I have all the nasty results of sheltering demodex for years, noticing the progressive damages but not thinking it all stemmed from this one and only culprit. Now i see the connection, i had a student microscope, i am getting a better one. Would you be interrested in researching with me?

  8. Terry says:

    After my opthamologist told me I had blepharitis, I started looking for more information. My right eye had been accumulating pus in the inside corner every hour. Antibiotics cleared it for a little while, but it was always coming back the next day. As I read about blepharitis on Google searches, I found a lot of information on Demodex mites. Demodex infestation explained a lot about my hair and face experiences over the last 15 years, (thinning, itching, falling out, male pattern baldness, acne), and it explained my puffy eye lids, constantly red eyes, and dark circles.

    Two weeks ago, I started washing my entire head and chest with a 50% diluted strength Tea Tree Oil mixture, taking care to gently scrub eyebrows, eye lids and moustache. After 3-4 days, the pus in my right eye was gone. The scalp itching was gone, and hair has started to regrow in bald areas on my scalp. I believe the daily use of 50% strength TTO has started to kill the Demodex mites. My plan is to apply the TTO treatment to head and upper body daily for the next 6 weeks, then back off to twice per week.

    Also, I am being careful to keep sheets, pillow cases, blankets washed weekly in hot water, followed by a hot dryer. I am very happy to have finally found the cause of my scalp and face issues, and I want to compliment your page as being very informative on Demodex.

    Thank you,


    • Pete says:

      Hi Terry, when you wrote “50% diluted strenght Tea Tree Oil mixture”; how much water \ tea
      tree oil did you mean? I’d like to give it a try but I’d prefer getting the dosage right before I start
      Thanks for replying

  9. Jayne Ferrell says:

    Demodex mites caused my Rosacea. A friend who is a research maven on many subjects told me to apply Sea Buckthorn oil after gently washing my face 3 times a day for 2 weeks. Since I was desperate to find a cure for my burning red face I did as was suggested and VIOLA no more Rosacea symptoms of any kind. Hope all Rosacea sufferers will give it a try.

    • Hi Jayne,

      thanks for your comment. I just wanted to note that Sea Buckthorn Oil is actually a nutrient so it is unlikely that it will kill demodex mites. Only something akin to an insecticide will be able to kill the mites.

      Sea Buckthorn Oil does have some beneficial effects on skin in general though, so perhaps that is why you saw an improvement.


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