Why are we blaming the mites....

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Why are we blaming the mites....

Postby Artist » Thu Jul 24, 2008 9:05 pm

....when it's the bacteria ON the mite that (according to the NRS funded researchers), is causing the real problem? It seems to me that we would have better luck targetting the bacteria since the mites seem painfully difficult to eradicate... Anyone treating mites might like to read this in detail.

From NRS study:
"In the new study, published in the British Journal of Dermatology, the researchers identified Bacillus oleronius> as distinct bacteria associated with Demodex mites. When analyzing blood samples using a peripheral blood mononuclear cell proliferation assay, they discovered that B. oleronius stimulated an immune system response in 79 percent of 22 patients with subtype 2 (papulopustular) rosacea, compared with only 29 percent of 17 subjects without the disorder."


From: http://www.rosacea.org/grants/research.php#Powell1
The entire article focuses on Demodex, but if you read it through you see that, according to the theory, the bacteria are the main culprit:

Mite-related bacteria may induce rosacea inflammation
Dr. Kevin Kavanagh, Department of biology, National University of Ireland, Maynooth, and Dr. Frank Powell, Consultant Dermatologist, Mater Misericordiae Hospital, Dublin.

Although they are normal inhabitants of human skin and cannot be seen, microscopic mites known as Demodex folliculorum may actually be something to blush about, as a new study funded by the National Rosacea Society (NRS) demonstrated for the first time that these invisible organisms may be a cause or exacerbating factor in rosacea.

"While it is well established that Demodex occur in far greater numbers on the faces of people with rosacea, it was uncertain whether they play a role in the development of the disorder," said Dr. Frank Powell, consultant dermatologist at Mater Misericordiae Hospital in Dublin, Ireland, who conducted the study along with colleagues at the National University of Ireland-Maynooth. "In other words, which came first, the mites or the rosacea? And now there is evidence that it might be the mites."

In the new study, published in the British Journal of Dermatology, the researchers identified Bacillus oleronius> as distinct bacteria associated with Demodex mites. When analyzing blood samples using a peripheral blood mononuclear cell proliferation assay, they discovered that B. oleronius stimulated an immune system response in 79 percent of 22 patients with subtype 2 (papulopustular) rosacea, compared with only 29 percent of 17 subjects without the disorder.

"The immune response results in inflammation, as evident in the papules (bumps) and pustules (pimples) of subtype 2 rosacea," Dr. Powell said. "This suggests that these bacteria found in the mites could be responsible for the inflammation associated with the condition."

Dr. Powell noted that the potential role for the bacteria in subtype 2 rosacea is also supported by the fact that effective treatment includes antibiotics that destroy B. oleronius. Interestingly, he said, antibiotics that are not harmful to these bacteria generally are not effective in the management of rosacea.

"Although the mechanism of antibiotics in treating rosacea is not definitively understood, it has long been suggested that they work through anti-inflammatory action," he said. "However, other anti-inflammatory drugs are ineffective in treating rosacea, and immunosuppressive agents such as steroids can ultimately make the inflammation worse."

The researchers concluded that their study shows consideration must also be given to the potential for antibiotics to affect microorganisms such as B. oleronius or other follicular or mite-related bacteria.

Publication of results: Lacey N, Delaney S, Kavanagh K, Powell FC. Mite-related bacterial antigens stimulate inflammatory cells in rosacea. British Journal of Dermatology 2007;157:474-481.
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Re: Why are we blaming the mites....

Postby David Pascoe » Fri Jul 25, 2008 2:37 am

Hi Artist,

I recently read the full paper "Mite-related bacterial antigens stimulate inflammatory cells in rosacea." Although they were able to extract 2 proteins from a bacterium from a mite and show that they produced an inflammatory response, they could only isolate the bacteria in 1 of 40 patients. The researchers were unable to say why this was the case, so it seems that building a link between demodex -> bacteria -> rosacea is held back by this.

I don't think too much can claimed about demodex bacteria just yet - one baby step at a time, sadly.

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Re: Why are we blaming the mites....

Postby Artist » Fri Jul 25, 2008 4:47 am

What?! That stinks. I somehow missed that. Is there a link to the paper? I'd love to read it if possible. Thanks! Artist
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Re: Why are we blaming the mites....

Postby David Pascoe » Fri Jul 25, 2008 4:52 am

There isn't a link as you need a subscription. I'll email you a copy.

This is an example of why just reading abstracts is misleading. I fall in to that trap all the time :(

The researchers aren't really trying to prove that demodex -> bacteria -> rosacea, but that is how we are reading their research.

I summarized this paper as baby steps demodex bacteria, one baby step at a time as I think it is such a small achievement gained via this paper.

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