Understanding Your Oil and Water Skin Type

I don't think you clarified the idea of one's water and oil balance well - so if you have dry skin, does that mean you lack water or oil? What about folks with oily skin - does this mean their skin is dehydrated and can only protect itself by producing more oil?

I have oily skin and although I've tried to forgo using moisturizer once (as Dr. Leslie Baumann stated oily folks should in her 'The Skin Type Solution'), I found my face to feel incredibly irritated/scratchy .. I've come to the conclusion that my face is dehydrated and needed ingredients with water & hydrating ingredients at its list, not oil-based ingredients.

@S: Your skin has water glands that make water and oil glands that make oil and they have nothing to do with each other. It’s the relative balance of oil and water on the surface of your skin made by each type of gland that determines which of the four facial oil and water skin types you have. If you have dry skin, you lack water, not oil. On the other hand, people with oily skin have too much oil and enough water. But if along with your oily skin you don't have enough water, then instead of having oily skin you have combination skin (both too much oil at the same time you don't have enough water; the excess oil tends to be greater in the "t-zone" while the deficit of water is more important on the cheeks). Lastly, you are completely correct with your conclusion: sounds like combination skin which as you concluded should never have oil put on it because of the oily component of combination skin and as you also concluded you need a moisturizer that is water based to restore the missing water caused by the "dry component " of combination skin.

Dr Schultz, I have a quick question. Why are oil and water not related? Isn't sebum supposed to reduce TEWL and thus "hydrate" the skin?

@Anson Ng: Oil and water are not related in their formation or production. Oil glands make oil, and water (sweat) glands make water. And you are absolutely correct that one of the roles of sebum is to coat the skin and thereby reduce TEWL (Transepidermal Water Loss), which effectively "hydrates" the skin by preventing loss of existing surface moisture. That is a fact of normal physiology which has been abused by skincare manufacturers. They promote oil as a "moisturizer" and unfortunately trick people who have dry (lack of water) skin into coating their skin with oil-containing products to seal in their existing moisture, which may or may not be effective. But this also runs the risk of clogging the oil glands of people who have a normal amount of oil, let alone causes acne outbreaks in people with both dry and oily (combination) skin. The best way to treat dry skin is with oil-free, water-based moisturizers that restore and correct the deficient water content without risking collateral damage to the oil glands.

Neal Schultz, M.D.

And you are absolutely correct that one of the roles of sebum is to coat the skin and thereby reduce TEWL (Transepidermal Water Loss), which effectively "hydrates" the skin by preventing loss of existing surface moisture.

Dr Schultz,
I'm sorry to inform that you are dead wrong about that quote above. Sebum does not prevent loss of existing surface moisture. This myth has been clearly debunked by the most famous name in dermatology, Albert Kligman. I can't stand when doctors give people misinformation.

"Sebum is an oily substance that is secreted onto the skin surface from glands located in the dermis. Although a number of useful functions have been proposed for sebum, proof that sebum performs any of them is lacking. In furred mammals an essential function of sebum is to supply 7-dehydrocholesterol, which is converted to vitamin D by the action of sunlight and then ingested by the animal as it grooms itself. In man, however, the location of 7-dehydrocholesterol has been shown to be the epidermis rather than sebum. Sebum may act as a waterproofing agent for fur, but humans obviously have little need for this function. Kligman has specifically disproved the notions that sebum improves the barrier function of skin, that sebum helps to regulate the water content of the horny layer by forming emulsions with sweat, or that sebum on the skin surface is fungistatic or antibacterial.(21) Kligman regards the human sebaceous glands as 'living fossils' that lost their usefulness to our species as we lost our fur.(21)

@Adam Goldstein: Thank you for providing this conversation with another view point. I however, respectfully disagree with your stance, even though as you point out, Dr. Kligman would agree with you. While certainly a pioneer in the field of acne and very prolific in his research, like many other notable researchers he had views, did research, and came to conclusions that were not all embraced by everyone in the professional community. Many of my peers (whether professors of dermatology at university medical schools or practicing clinical dermatologists who are "on the front lines" taking care of most of the patients) would disagree with Dr. Kligman in his conclusion that sebum (i.e., oil) is not important in reducing TEWL and maintaining the skin's hydration; we believe that it is, and I'll explain why. Since DermTV is about helping people with clinical real life skin issues, I'd like to cite the common condition of "senile pruritus" (i.e., itching skin in older people) as clinical evidence of the all important role of skin sebum in maintaining skin hydration directly by reducing TEWL. As everyone ages (and especially past the age of approximately sixty), their oil glands produce less oil and ultimately (in most cases) become dysfunctional and make none. This loss of sebum production is the direct and proximate cause of the increased drying and relative dehydration of the epidermis that causes their intolerable itching (i.e., senile pruritus). This is the most direct example of why to me and my peers, sebum does in fact help the skin maintain surface moisture and hydration, as I mentioned in my comment above.

Ok. So if you are indeed correct about this, which am not doubting, I guess i permanatly messed up my skin because....

i took accutane 3 years ago and my skin still does not produce sebum. There is never any sebum on the surface of my skin. If what you are saying is true doctor, should I be concerned about this, and how could i get my sebaceous glands to produce sebum again? I am very upset because i had mild acne and my dermatologist gave me a 6 month course of accutane when i was clear by the first week. I weighed 165 lbs and i was given 40mgs for 2 months and 80mgs for 4 months. Now I still dont produce sebum. Now i think there is alot of truth to what you say because my skin is starting show many fine lines. Preaccutane, my skin was oily and i had no fine lines. Can you please provide me with a course of action I can take now to increase my sebum production because I am extremely down about my prematurely aging skin due to lack of sebum. Thank you so much Doctor, and I never meant to try and prove you wrong.

In response to your example of older people having skin issues becaue of lack of sebum, i just wanted to also hear your input as to what Kligman feels about that.

Kligman says,
Kligman drew attention to prepubertal children, who produce almost no sebum, to support his thesis that skin does not depend upon sebum for maintaining its barrier to water loss: "...there can be no doubt of the insignificance of sebum as a waterproofing material." (14) Our recent studies at the other end of the human age spectrum have supported this conviction. In a survey of sebum secretion rates and the incidence of dry skin among subjects aged 65 to 97, no correlation was found between sebaceous gland activity and the presence or severity of dry skin (34). Kligman recognized that sebum could mask the scaliness of dry skin without producing any actual change in the condition: "Sebum, like any oil, has some emollient or smoothing effect when a sufficient quantity is rubbed into dry, scaling skin." (14) In spite of the clear inference to be drawn from the cutaneous characteristics of children and the experimental data obtained from the elderly, it remains difficult to dispel the myth that low sebum secretion rates cause dry skin. It is a rare individual who realizes that "dry" is not the obverse of "oily".

Here's the citation for that study mentioned in the previous post about how there was no correlation between the incidence or severity of dry skin in the elderly, and their level of sebum production: Frantz RA, Kinney CK, Downing DT: "A study of skin dryness in the elderly" Nursing Res 35: 98-100, 1986.

So how does Dr. Schultz explain the apparent lack of of effect of sebum on dryness at BOTH ends of the age spectrum (prepubertal children, and the elderly)?

@Adam: @Bryan: First and more important, I want to address your personal issue regarding prior use of Accutane and your current absence of skin surface sebum. Whether or not your oil glands eventually regain sebum producing capability, I can offer you the following encouraging information:

(1) The absence of your own endogenous sebum can be functionally compensated for by applying moisturizers containing specific ingredients. I say " functionally compensated" to mean that while these ingredients are not chemically identical to the composition of sebum lipids, they can help prevent TEWL from your skin almost as well as sebum and in some cases even better because of their hygroscopic and/or hydrophilic qualities. These ingredients to look for are hyaluronic acid, dimethicone, silicone, glycerin, shea butter, and especially products like Atopalm which incorporate Multi-Lamellar Emulsion technology which are great at restoring effective skin surface lipids.

(2) The fine lines you are starting to see can be easily helped. In addition to using moisturizers with the ingredients mentioned above, for the reasons discussed in several DermTV segments (Why You Need to Wear Sunscreen Every Day, The Three Essential Daily Skin Care Products, How to Choose the Right Sunscreen, Why You Should Exfoliate Every Day, and How Antioxidants Protect Your Skin) I suggest the daily use of an effective sunscreen (the lines you are seeing at this time may in part be due to photoaging and not just the absence of sebum), a gentle chemical exfoliant (like glycolic), and a topical Vitamin C antioxidant product every night.

(3) Allow a few months to see a meaningful improvement.

Second, I would like to try to help further clarify this truly confusing sebum subject. Your citation of Dr. Kligman's work is accurate and you will be pleased to know it is also cited in most major textbooks of dermatology. That is because he is one of the few people who did research on this perhaps less than exciting subject. And to be "fair and balanced," some also admit (as recently as 1992, almost thirty years after Kligman's work) that, "The physiologic significance of sebum in humans remains largely an enigma," (Moschella & Hurley, "Dermatology", 1992), but then goes on to list the alleged roles of sebum (TEWL, anti-fungal, Vitamin D precursor, etc.) and then while concludes that these roles are not proven in the laboratory implies that clinical human patient experience (like what I mentioned concerning age related, "senile pruritus," also called asteatotic eczema) is at variance with Kligman's research. And to your point, infants make little or no sebum but do not suffer from asteatotic eczema /senile pruritus. The complete answer therefore may be that there is a hybrid mechanism of maintaining epidermal hydration that may be a function of the additive effects of the integrity of the dermal / epidermal border barrier as well as the presence of  surface sebum which may actually come from two sources: oil glands in the dermis and the epidermis itself (more on this in the next paragraph).

The largest and most comprehensive text on dermatology is a four volume 3,400 page book edited by Rook and Wilkinson titled, "Textbook of Dermatology." They don't bring us any closer to a consensus by starting the section with, "Several functions have been ascribed to [human] sebum but they are by no means undisputed." In their discussion of Kligman's work, they (Rook et. al.) get around Kligman's argument of sebumless, non-dry infant skin (as part of Kligman's evidence for sebum not being important in TEWL) by stating that, "sufficient lipid is derived from the epidermis itself." They then cite a paper from the (prestigious), "British Journal Of Dermatology," (1964), which is titled, "The Protective Effect of the Sebaceous Layer."

Bottom line: it's very important to understand the evolution of our knowledge which is incomplete and still comprised of a limited set of facts from which we then must draw our own conclusions. I have an open mind to the probable multi-factorial mechanism of the regulation of epidermal hydration and believe, based on my reading and more importantly 30+ years of treating the disease and suffering resulting from epidermal dehydration, that sebum plays at least an important role in that process. The following quote from my medical school orientation program continues to resonate in my mind: "Treating patients without the benefit of books is like going to sea without any charts. Learning medicine from books without treating patients is like not going to sea at all."

In relation to two of the subjects discussed here, I have a slightly different question.

For those of us who have who have oily skin, many have (perhaps wrongly) taken to multiple washings per day, which, in the end, doesn't do much to stop the oiliness from returning rapidly and sometimes in a greater amount.
I've heard this condition referred to as "reactive seborrhoea" before, but I can't find much about it in medical journals or other reputable resources. Does such a condition exist?

For myself in particular, I've used harsh topicals (you name, I've tried it) over the past 10 years, leaving my already super-sensitive skin incredibly ravaged.

The overarching question is: are dry and oily not mutually exclusive? When I get out f the shower, my face is extremely fragile and dry, and it seems to overcorrect in order to "moisturize." That would lead me to believe my skin is "dry" by it's nature, but becomes oily to keep a hold on what water it has. Does this make sense?

@Grant: You are correct. Reactive seborrhea does not exist despite its popularity in the lay literature. Regarding your second question, to the best of our knowledge, oil gland production is solely under the influence of hormones with no positive feedback loop connected to the surface condition of the skin’s water or oil.

Dr. Shultz, I just wanted to say great discussion you have going on here! Informative and enlightening! Thank you also for personally responding to my email regarding my excessive oiliness. You suggested that Accutane might be an option for me. (note: this has also been suggested in the past by one of my Derms). But I thought it was taken off the market recently? Is it available still as Isotrentoin? or other trade name? And would it work for the excess sebum on my scalp and body as I have horribly oily hair and back/chest as well?

@Angela: Thank you very much. While the brand Accutane is no longer being manufactured, the brands Amnesteem, Claravis and Sotret of isotretinoin are still available. Isotretinoin can help the excessive oiliness of your scalp ,back and chest as well.