June 2001

Tip of the Month

The age of approximately 2 to 6 years is an "acne free zone," during which acne vulgaris rarely occurs.

Newborn infants may have an acne eruption on the nose or cheeks, probably caused by hormonal changes as the fetus develops. Acne in newborns usually clears in a matter of weeks, without treatment.

The eruption called infantile acne may appear in the weeks to months after birth and remain for several months. It may clear without treatment, but persisting or severe infantile acne may have an underlying metabolic cause that should be investigated by a pediatrician and dermatologist.

The "acne free zone" of approximately 2 to 6 years is believed to be due to the very low production of sebum in sebaceous follicles at this time of life (Click on Why and how acne happens for an explanation of the relationship between sebum production and acne). The low sebum production between ages 2 and 6 is probably associated with the low levels of androgenic hormones in the child’s developing body. Sebum production is known to be under a degree of androgenic control.

The association between acne and increased rate of sebum production later in life is supported by the evidence that average rates of sebum secretion are higher in persons with acne than in persons without acne. Sebum production begins to increase as the child matures toward adolescence and hormone patterns change with growth and development.

Fact of the Month

This month completes the Fact of the Month three-part series updating information about acne treatments. Part 1 covered over-the-counter treatments. Part 2 discussed prescribed topical medications. Parts 1 and 2 can be accessed in AcneNet Updates for the two previous months. Part 3, this month, is an update on systemic medications—oral antibiotics, hormone therapy, and isotretinoin.

Oral Antibiotics

Broad-spectrum antibiotics have been a mainstay of systemic therapy for moderate to severe and persistent acne for many years. Numerous studies have provided evidence supporting the effectiveness of oral broad-spectrum antibiotics. The anti-acne activity of oral antibiotics appears to include physiologic effects in the sebaceous follicle as well as reduction of bacterial populations in the follicle.

Oral tetracycline has a long history in the treatment of acne, and remains one of the most widely used. A typical tetracycline regimen for treating moderate to severe acne is a starting dose of 500 to 1000 milligrams a day, decreased as improvement is noted. Long-term, low-dose tetracycline therapy may be continued for many months to maintain suppression of acne. Higher doses may be prescribed for very severe acne, with regular monitoring for systemic side effects. Tetracycline may cause staining of teeth in children, and should generally not be taken by children younger than 8 years of age. Oral tetracycline may cause permanent teeth staining or skeletal defects in a fetus and therefore should not be taken by a woman who is pregnant.

Oral erythromycin is an alternative to tetracycline that is safe for use in pregnant women and young children.

Oral minocycline and doxycycline are synthetically derived from tetracycline. Some evidence suggests that these antibiotics may be more effective than tetracycline in treating acne. Minocycline has a long history of use in the treatment of acne. Doxycycline may induce sensitivity to sunlight. Neither should be taken by pregnant women.

Hormonal Therapies

Androgenic ("male") hormones are known to have physiologic effects on sebaceous follicles that promote the development of acne. The purpose of hormonal therapy is to block or lessen acne-promoting effects of androgenic hormones.

Estrogen is a "feminine" hormone that counteracts effects of androgenic hormones and decreases sebum secretion in the sebaceous follicles. Estrogen has wide-ranging physiologic effects in the body and its use must be closely monitored—often by both a gynecologist and a dermatologist. The use of estrogen alone in the treatment of acne may be indicated in carefully selected patients.

Estrogen-containing oral contraceptives are prescribed more frequently than estrogen alone in hormonal therapy of acne in females. The effects of estrogen are balanced by other hormonal constituents of oral contraceptives. While oral contraceptives have a better safety profile than estrogen alone in treating acne, their use must be monitored for side effects of nausea, weight gain, menstrual spotting and breast tenderness. Hormonal therapy may be a treatment of choice for women whose acne does not respond to other medication.

Corticosteroids

These powerful anti-inflammation drugs may be prescribed for short courses to treat very severe acne. Their metabolic effects limit long-term use. Low-dose corticosteroids are helpful in specific instances—for example, to suppress excessive secretion of androgenic hormones. Corticosteroids can induce development of steroid acne with prolonged use.

Other Hormone Therapies

The anti-androgen spironolactone reduces sebum production and improves acne in some patients. Side effects include irregular menstruation in women, breast tenderness, headache and fatigue. The anti-androgen may be used along with an oral contraceptive to reduce irregular menstrual bleeding.

Flutamide is an anti-androgen sometimes prescribed together with an oral contraceptive to treat acne and hirsutism (excessive growth of facial and body hair) in women. It should not be taken by pregnant women.

Isotretinoin

Isotretinoin is the most effective drug available for treatment of severe cystic acne and acne resistant to other medications. It is a synthetic retinoid. The retinoids are molecules of the vitamin A family of molecules (Click on Topical retinoids in Part 2 of this series for discussion of the biochemical and physiologic activity of the retinoids as they relate to the treatment of acne). Isotretinoin is a potent drug, usually reserved for treatment of very severe cystic acne and acne that is resistant to other medications. It is very effective in treating all forms of acne; the remissions achieved with isotretinoin usually last for many months to many years.

A number of side effects are associated with isotretinoin therapy, the most serious being the potential to cause severe birth defects to a developing fetus. The most common side effect of isotretinoin therapy is dryness of the skin and mucous membranes. Other, less common, side effects include nausea and vomiting, bone and joint pain, headache, thinning hair, psychological depression, and changes in blood and enzyme profiles monitored in regular follow-up examinations. Regularly scheduled monitoring for side effects is recommended by the physician. For most persons treated with isotretinoin, side effects are tolerable and not a reason to discontinue therapy before remission is achieved. It is imperative that women of childbearing potential follow the pregnancy prevention program and guidelines. Women who are planning a pregnancy, are pregnant or are nursing must not use isotretinoin. It is recommended that women planning a pregnancy discontinue the use of isotretinoin for one month.

The effectiveness of isotretinoin in treating severe acne is shown in the following before-and-after photos:

Severe acne before treatment with isotretinoin.

Severe acne before treatment with isotretinoin.

Acne that had been severe, after isotretinoin therapy.

(Photos used with permission of the American Academy of Dermatology National Library of Dermatologic Teaching Slides and the Sulzberger Institute for Dermatologic Education)

Question of the Month

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

What is the difference between sweat glands and sebaceous glands? Does acne have anything to do with plugged sweat glands?

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

Answer to last month’s Question of the Month

Last month’s question was:

Is acne that appears for the first time in adulthood different from acne that appears in adolescence?

Answer: Acne has a specific definition as a disease of sebaceous follicles. This definition applies to acne that occurs at any age. However, it may be important to look for an underlying cause of acne that occurs for the first time in adulthood.

Current understanding of the causes of acne vulgaris is described in the Main Text section Why and how acne happens. In brief summary, acne vulgaris develops when excessive sebum production and abnormal growth and death of cells in the sebaceous follicle result in plugging of follicles with a mixture of sebum and cellular debris and formation of comedones (blackheads and whiteheads). Bacteria in the follicles—chiefly Propionibacterium acnes, the most common bacterial colonist of sebaceous follicles—may contribute to the inflammation of acne by release of metabolic products that cause inflammatory reaction. The pathogenic events, which cause disease, in the sebaceous follicle are believed to be due in large degree to changes in levels of androgenic (male) hormones in the body—a circumstance usually associated with growth and development between ages 12 and 21.

Some acne investigators believe that although this understanding is generally correct, there is more yet to be learned about the causes of acne vulgaris. 

Acne that appears after the age of 25-30 years is (1) a recurrence of acne that cleared up after adolescence, (2) a flare-up of acne after a period of relative quiet—for example, during pregnancy, or (3) acne that occurs for the first time in a person who had never previously had acne.

Acne that occurs in adulthood may be difficult to treat if there are multiple recurrences. Some patients with severe recurrent acne have undergone repeated courses of treatment with the potent systemic drug isotretinoin. 

Acne flares in association with pregnancy or menstruation are due to changes in hormonal patterns.

Acne that appears for the first time in adulthood should be investigated for any underlying cause. Drugs that can induce acne include anabolic steroids (sometimes used illegally by athletes to “bulk up”), some anti-epileptic drugs, the anti-tuberculosis drugs isoniazid and rifampin, lithium, and iodine-containing drugs. Chlorinated industrial chemicals may induce the occupational skin disorder known as chloracne. Chronic physical pressure on the skin—for example, by a backpack and its straps, or a violin tucked against the angle of the jaw and chin—may induce so-called acne mechanica. Some metabolic conditions may cause changes in hormonal balance that can induce acne.

Some lesions that appear to be acne may be another skin disorder such as folliculitis—infection and inflammation of hair follicles—that require different treatment than acne. Acne that appears for the first time in adulthood should be examined and treated by a dermatologist.