Rosacea and Seborrheic Dermatitis

Please note: In my book, Rosacea 101, (published in October 2007) in Chapter 2, Rosacea Mimics, page 9, you can read an updated version in my book of what I wrote below about Seborrheic Dermatitis which was used as the basis for this subject. Look on page 11 about SD. My new book is a comprehensive basic rosacea 101 knowledge for rosacea newbies who want to learn about the conventional and alternative treatments for rosacea. It is not uncommon for SD and rosacea to co-exist on rosacea sufferers.

The article below may help you if you have been diagnosed with SD since the real cause may be a fungus fungi called Malassezia Globosa.

Malassezia globosa and restricta: breakthrough understanding of the etiology and treatment of dandruff and seborrheic dermatitis through whole-genome analysis.

Dawson TL Jr.

The Procter & Gamble Company, Cincinnati, Ohio 45252, USA. dawson.tl@pg.com

Dandruff and seborrheic dermatitis (D/SD) share an etiology dependent upon three factors: sebum, microbial metabolism (specifically, Malassezia yeasts), and individual susceptibility. Advances in microbiological and analytical techniques permit a more detailed understanding of these etiologic factors, especially the role of Malassezia. Malassezia are lipid-dependent and demonstrate adaptation allowing them to exploit a narrow niche on sebum-rich skin. Work in our and our collaborators' laboratories has focused on understanding these adaptations by detailed analysis of biochemistry and gene expression. We have shown that Malassezia globosa and M. restricta predominate on dandruff scalp, that oleic acid alone can initiate dandruff-like desquamation, that M. globosa is the most likely initiating organism by virtue of its high lipase activity, and that an M. globosa lipase is expressed on human scalp. Considering the importance of M. globosa in D/SD (and the overall importance of commensal fungi), we have sequenced the M. globosa and M. restricta genomes. Genomic analysis indicates key adaptations to the skin environment, several of which yield important clues to the role Malassezia play in human disease. This work offers the promise of defining new treatments to D/SD that are targeted at changing the level or activities of Malassezia genes.

According to this Procter and Gamble, Pyrithione Zinc (PTZ) is effective against it:

"Pyrithione Zinc (PTZ) is a potent monographed anti-fungal agent against M. globosa. It treats seborrheic dermatitis/dandruff and provides symptomatic relief, reducing the irritation response while inhibiting the causal agent.4 The particles that comprise this anti-fungal can be engineered into flat platelet shapes to deliver optimized scalp coverage resulting in improved efficacy." source

Many rosaceans report that they have SD along with rosacea and this report confirms this:

"A number of leading Canadian dermatologists have observed that their rosacea patients often complain of other skin conditions, most notably seborrheic dermatitis, other forms of eczema and psoriasis. A recent Canadian study has confirmed these clinical obeservations and suggests than many rosacea patients (74%) do in fact have other dermatological conditions*....While the association between rosacea, a highly sensitive skin condtion, and seborrheic dermatitis is still not fully understood, both condtions can be effectively treated and controlled. Your family physician or dermatologist is best suited to provide you with a proper diagnosis, treatment plan and counseling...Seborrheic dermatitis affects 3-5% of the general population..." source > Rosacea - Itching Relief from Seborrheic Dermatitis, Rosacea Awareness Program -
http://rosaceainfo.com/enSeborrheic%20Dermatitis%20(E).pdf

* Rosacea: A Review of Family History and Ancestral Community of Origin - W.P. Gulliver et al. Journal of Cutaneous Medicine and Surgery, CDA 76th Annual Conference, Volume 5, 37, (2001).

This subject is apparently a controversy since the International Rosacea Foundation has claimed that "35% of rosaceans have seborrheic dermatitiis" and there are no clinical studies to substantiate this claim. source >

http://internationalrosaceafoundation.org/dermatitis_factor.html

Ketoconazole USP 2% topical gel was evaluated in subjects with severe seborrheic dermatitis source pdf source

However, there are reports in yahoo groups that physicians have difficulty distinguishing between SD and rosacea. Read this report >

http://health.groups.yahoo.com/group/rosacea-support/message/54095

By the way, if you wish to join a support yahoo group for SD >

http://groups.yahoo.com/group/seborrheic-dermatitis-support/