Seb Derm & Rosacea Studies?

[Artist]

Maybe David or Dan can answer this one.. Have there been any studies on Seborrheic Dermatitis and Rosacea? Now that the genetic code for the organism causing seborrheic dermatitis has been defined, the mechanism by which the yeast causes seb derm has been explained. The main points are:

M. Globosa (the seb derm causing yeast) feeds off of our skin sebum
It uses skin lipase extensively by breaking it down
The breakdown product of lipase (Oleic Acid) is extremely irritating to skin

"THE ETIOLOGY: MALASSEZIA LIPASE ACTIVITY
As the Malassezia globosa microorganisms consume sebum, they leave behind oleic acid. Oleic acid is a component of human sebum that is intensely irritating when it is isolated, and oleic acid has been shown to induce dandruff-like flaking when scalp conditions are right.9, 10 "
From: http://www.pgbeautyscience.com/defining-issues.html

So, what happens, even with mild seb derm, is you have inflammation from the Oleic Acid, and any of the following (but not required): flakes or scaling, tight dry feeling, redness/inflammation, you may be oily or not, you may have "patches" or not, itching sometimes occurs. Also, the skin cells slough off much more quickly (2-3 times faster than normal), so you have clumping off of skin - not good for rosacea since we need that barrier. Again, it may not be obvious. You may not see big skin clumps but still have this going on.

Another factor is that people have varying resistances to M. Globosa. Some are able to naturally inhibit the yeast, while others are not - some are just more resistant. Also, resistance changes over the course of one's life. So that, for example, during times of stress, you may be less resistant to this organism and have a flare of seb derm.

So, it seems that the M. Globosa effect on rosacea should be studied. It seems to me that even low levels of this yeast on rosacea skin would cause issues becuase of the Oleic Acid breakdown product. Why not eliminate that trigger? I tend to wonder if M. Globosa plays a bigger part in rosacea than we realize.

Cheers!

Artist

[Quiller]

Maybe you can find a fragrance/preservative-free pyrithione zinc product to try on your rosacea areas.

I wonder if Skin Actives would be interested in offering pyrithione zinc for seb-derm/rosacea (so we don't have to use H & S on our faces).

My seb-derm areas tolerate the H & S well, but I don't want to put it on my cheeks. I'm very interested in the fungal theory, though, because that would explain why high concentrations of sodium bicarbonate are still controlling my inflammation.

[David Pascoe]

I was always reading the p. ovale was the culprit for SD.

eg.

http://www.aafp.org/afp/20000501/2703.html

Pityrosporum ovale, a lipophilic yeast of the Malassezia genus, has been implicated in the development of this condition.3 It has been suggested that seborrheic dermatitis is an inflammatory response to this organism, but this remains to be proved.4 P. ovale is present on all persons. Why some persons develop seborrheic dermatitis and others do not is unclear. The colonization rate of involved skin by this organism may be lower than that of uninvolved skin.3 Nonetheless, the fact that seborrheic dermatitis responds to antifungal medications is strongly suggestive of the role of yeast in this disorder.

So the link from Proctor and Gamble that Artist posted above is really interesting. It suggests that we don't have to use nizoral (but it doesn't actually say not to, it does work) but Pyrithione Zinc (PTZ) is an excellent anti-fungal against M. globosa, the true culprit of SD.

[Artist]

There is a fragrance free, relatively gentle facewash with Pyrithione Zinc (PTZ) as the active ingredient. Born to be Mild cleanser by Dermadoctor:

http://www.dermadoctor.com/product.asp? ... &AID=15750

I have it, and I think I am only going to need it about twice a week. I wouldn't use it every day - too strong for rosacea for daily use. Twice or three times a week will work fine.

"Pityrosporum" was renamed or re-classified as Malassezia (not sure why). For a while, scientists thought the causative organism was a different strain (M. Furfur, for example) that happens to thrive in culture (petri dish environment). But, they later realized the real strain was M. Globosa. The reason they missed it was that M. Globosa didn't grow well in a petri dish. So, lots of globosa thrives on our skin, just not in a petri dish, so they didn't see it before. The scientists knew M. Globosa must be the culprit because of it's very high level of lipase activity - breaking it down to form the irritating oleic acid. Now that they knew the exact organism, they moved forward with learning it's genetic code. So, for many years we knew it's probably caused by a Malassezia yeast, but weren't sure of the mechanism. At least, this is what I gather from searching on the internet. So, a dizzying array of products were created and advertised, some better than others.

I think the big deal for me is that I now understand the mechanism and realizing how irritating seb derm actually may be to rosacea. Also, knowing the ingredient that works most effectively against this strain.

Cheers!

Artist