AcneNet This Month
April 2000

Tip of the Month

Many years ago, sunlight was sometimes recommended as a treatment for acne.

That was then. This is now. Today, dermatologists warn against intense, repeated exposure to sunlight. It is recognized now that the kind of intense, repeated exposure one gets in sunbathing is a major risk factor for melanoma, the deadliest form of skin cancer.

The ultraviolet radiation of sunlight can also damage the skin over time, making it inelastic and old-looking.

It is known today that while sunlight does suppress the inflammation of acne, it is not a good idea to "cook" yourself in repeated episodes of sun exposure. If intense sun exposure causes the skin to burn and peel, the resulting inflammation may even contribute to a worsening of the appearance of acne.

In addition, if you are under treatment for acne, some acne treatments cause the skin to be extremely sensitive to sunlight. This creates the possibility of a severe reaction to intense sun exposure.

Some people with acne want to get just enough sun exposure for a nice tan—using a suntan to cosmetically cover up the appearance of acne. The problem is that repeated sun tanning may cause additional skin problems. The use of ultraviolet light for treatment of acne should be under the supervision of a dermatologist.

Click on Acne treatments in for more discussion.

Fact of the Month

When a person with acne asks "Why me?", one part of the answer is "Because you are human".

Acne is a skin eruption that does not naturally occur in any animal, even though a number of animals have secretions of sebum, the fatty substance that is associated with comedo formation.

Sheep, rabbits and rodents secrete sebum, for example, but human sebum is uniquely different in its composition. More than half of human sebum is composed of triglycerides and free fatty acids, whereas in sheep, rabbits and rodents sebum contains less than 10 percent of free fatty acids and almost no triglycerides. Free fatty acids are a component of sebum that is believed to irritate skin tissue and contribute to the inflamed look of acne after a comedo forms. The function of free fatty acids in human sebum is not entirely understood, but the ratio of free fatty acids to other lipids in human sebum is uniquely human.

Sebum is produced in sebaceous follicles, and in humans the major stimulus to sebaceous gland development and secretion is the male hormones called androgens. When androgen production goes into high gear during adolescence, there can be a resulting increase in sebum production, depending on individual sebaceous-gland response to androgen stimulation. Human sebum has great biochemical complexity, containing in addition to free fatty acids and triglycerides, other lipids including cholesterol, squalene and waxes. The association of sebum with acne can be viewed as a side effect of complex biochemical activity.

Sebum is a component of the oily plug found inside a comedo. The composition of this oily material is 20 to 60 per cent water, sebum, dead skin cells and cell fragments, cellular proteins, and microorganisms (including Propionibacterium acnes). The contribution of P. acnes to acne is a proven fact, but the contribution of P. acnes and acne and acne inflammation probably varies considerably between individuals. Watch for a future AcneNet Update where the causes of inflammation are discussed in detail.

(Early in the Twentieth Century, P. acnes was thought to be THE cause of acne, but this simplistic view is no longer accepted. The sebaceous follicle is a normal environment for P. acnes, although not all sebaceous follicles contain P. acnes. If P. acnes sometimes contributes to the development of acne, an underlying cause may be some change in the biochemical inter-relationships between P. acnes and its environment that induces P. acnes to behave differently and contribute to inflammation. Antibiotics are often effective in treating acne, but the reason for their effectiveness may not be entirely due to antibacterial activity. Some antibiotics also have anti-inflammatory properties, in that they cause decreased production of substances that attract white blood cells to the acne lesion, and induce rapid clearing of the white blood cells called macrophages).

Since sebum is an oily substance, is it possible to control sebum production through diet? The answer is NO. Because there might seem to be a direct association between "oily face" and "fatty foods", it used to be thought that avoidance of high-fat foods could control acne. Now it is known that sebum production is largely under hormonal control, and the proper role of diet is to promote general good health.

Question of the Month

Each month we pose a question that is answered the following month. This month’s question:

The mother of a 12-year-old daughter writes:

My daughter is beginning to have outbreaks of blackheads, whiteheads and pus-filled pimples. As a teen-ager and young woman, I had severe acne and was treated twice with isotretinoin (Accutane). I was a virtual recluse because of my appearance until I was in my early 20s. At age 40 I haven’t had any acne outbreaks for five years, but I have many acne scars on my face. I’m afraid my daughter is beginning to develop acne and I don’t want her to experience the emotional pain and isolation I went through. What should I be doing for her?

We’ll have an answer, and a discussion of the answer, on AcneNet next month.