How microbes may cause Rosacea

Written by on August 14, 2015 in Demodex Mites, What Causes Rosacea? with 2 Comments

There are several microbial agents that appear to have their fingers in the rosacea pie;

  • Demodex folliculorum,
  • Bacillus oleronius,
  • Helicobacter pylori,
  • Staphylococcus epidermidis, and
  • Chlamydophila pneumoniae.

A 2014 paper in the Journal of the American Academy of Dermatology attempts to put the potential microbiomes into perspective. This Galderma funded paper seeks to “propose an alternative theoretical framework for understanding the complex role of microorganisms in the development or progression of rosacea.”

A summary of the proposed role appears below. Unfortunately, as you will see, this is all very complex and so far there is still no agreement on how all of the possible interplays between microbes may lead to rosacea being present.

For more information on this paper.

Reprint requests: Anna D. Holmes, PhD, Galderma Laboratories LP, 14501 North Freeway, Fort Worth, TX 76177. E-mail: anna. (remove space from name)

Proposed Role for Microorganisms in Rosacea

(click for larger image)

Step 1: Unaffected rosacea-prone skin has increased expression of microbe sensing machinery and normal flora.

Step 2: Commensal agents may act as trigger factors for rosacea inflammation through activation of pattern recognition receptors (PRR) or altered tolerance.

Step 3: Physiologic and inflammatory changes in rosacea skin may create a microenvironment that is suitable for altered growth or metabolism
of microbial species.

Step 4: Alterations in commensal flora or introduction of noncommensal agents may result in further activation of inflammatory pathways, worsening of disease, or appearance of subtype-specific symptoms.

Step 5: An immune response that results in clearance of the exacerbating agent may impart temporary relief from rosacea symptoms and a return to microbial homeostasis. AMP, Antimicrobial peptide.

The hypotheses presented here are reflective of a concentration of research in rosacea pathophysiology and the microbiome of the skin. With the
exception of Demodex and H pylori, the association of rosacea and microorganisms is supported by limited, small, and underpowered studies.

Article Abstract

Potential role of microorganisms in the pathogenesis of rosacea

J Am Acad Dermatol 2013;69:1025-32.

Anna D. Holmes, PhD

From Galderma Laboratories LP. Funding provided by Galderma Laboratories LP, Fort Worth, TX.

Disclosure: Dr Holmes is employed by Galderma Laboratories LP, Fort Worth, TX

Rosacea is a skin condition of abnormal inflammation and vascular dysfunction. The active contribution of a microbial agent in the development or progression of rosacea continues to be debated.

Research supports the presence of commensal Demodex folliculorum mites at increased density in the skin and associates Helicobacter pylori infection of the gut with rosacea. Fewer studies implicate Staphylococcus epidermidis, Chlamydophila pneumoniae, and the Demodex-associated bacteria Bacillus oleronius.

No research, however, provides a mechanism by which colonization by a microorganism translates to manifestation of the condition. Prevailing and emerging principles in the biology of the microbiome and the pathophysiology of rosacea may help to reconcile these lingering questions.

Here the microorganisms implicated in rosacea are reviewed and the reaction of the microbiome to inflammation and to changes in microenvironments and macroenvironments are discussed to explain potential roles for microorganisms in rosacea pathophysiology.

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About the Author

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

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2 Reader Comments

  1. Comment via email.

    “Oh my goodness my ears went up when mention of Chlamydophila pneumonia was made. Given the high incidence of asthma in rosacea subjects it is very plausible. I have considered the treatment recommendations of a Dr. David Hahn who recommends long term antibiotic prescription for this. I hesitated to try, but am increasingly giving it consideration. He wrote a book The Asthma Cure. I suffer from both maladies intermittently. Not quite right ever though! Great article David Pascoe.

  2. Merle says:

    Why does the Canadian Medical Association not recognize Demodex as a condition to be treated?

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