Treating acne

Tagged:  

Section: OTC Options
(This article is one in a series on non-prescription drugs)

Acne.

The very word is enough to halt most teenagers in their tracks. Yet rare is the adolescent who can escape the skin disorder completely.

"It is almost universal," says Alan R. Shalita, M.D., chairman of the dermatology department at State University of New York. Shalita and other experts estimate that 85 percent of the U.S. population between the ages of 12 and 25 suffers from some form of acne vulgaris, the medical term for the condition.

Though acne often is a simple case of pimples, it sometimes can erupt as unsightly pus-filled sores with the potential to disfigure. Ache may fracture self-esteem in the teen years, but this dermatological rite of passage generally is history by early adulthood.

But not always. Cases of the ailment occur occasionally in pre-teens and in older adults. Sometimes women experience acne flare-ups at certain stages of the menstrual cycle or after discontinuing oral contraceptives. Experts say stress and heredity also can play a part.

The American Academy of Dermatology says it's a good idea for acne sufferers to check with a dermatologist to ensure the skin condition really is acne. Rashes from other sources such as makeup and oral medicine can create acne-like symptoms.

Severe acne requires a doctor's attention to prevent permanent scarring. (See "Acne Agony" in the July-August 1992 FDA Consumer.) But milder cases often yield to treatment with over-the-counter (OTC) products. Dozens of products are available in varying strengths as creams, lotions, gels, and cleansers. In its review of OTC drugs, the Food and Drug Administration approved sulfur, resorcinol, and salicylic acid for OTC treatment of acne. The agency determined that more safety studies are needed for another ingredient, benzoyl peroxide. All these ingredients were on the market before 1972, when FDA began a review of OTC drug products.

Some Unanswered Questions
Benzoyl peroxide products have been sold for more than 25 years. FDA and the dermatological community have long considered the drug to be an effective nonprescription acne medicine.

But FDA officials are concerned about what happens when skin treated with benzoyl peroxide is exposed to the sun. Study data are inconclusive at this time.

Scientists call chemicals and radiation that can start tumor growth "initiators." The sun's ultraviolet light is a known initiator. Substances that increase tumor development when an initiator is present are called "promotors." Benzoyl peroxide is considered a promotor.

Researchers have observed that benzoyl peroxide has a tumor-promoting effect in mice exposed to a chemical initiator. They don't know yet what effect the sun may have specifically on skin treated with benzoyl peroxide. Until research can establish or disprove a link, FDA plans to require extra warning and direction statements on benzoyl peroxide product labels. The agency published a Federal Register notice on Feb. 17 to solicit comments on its proposed labeling changes. Deadline for comments is May 18.

Though studies in mice showed that benzoyl peroxide did not cause the growth of tumors initiated by the sun, these studies did not resolve the issue, say FDA officials. The research used an inadequate number of mice and did not show conclusively whether benzoyl peroxide actually increased tumors. Another study in progress with more than 100 mice should allow scientists to make more valid conclusions.

Researchers also are conducting tests to determine what effect benzoyl peroxide has on mice and rats for the lifetime of the animal. When these tests are completed, FDA will evaluate results and decide how the information will affect the use of benzoyl peroxide products.

Other existing studies further cloud the association between the drug and cancer. For example, a recent Canadian survey-type study queried benzoyl peroxide users to find out if they had developed skin cancer. Results showed that users of these products did not have a higher risk of developing tumors or cancer. Though the study generally was well-designed and furnished useful information, FDA officials say, it did not group subjects for skin cancer risk by duration of use and time since last use of the drug. The survey also did not consider the reasons for benzoyl peroxide therapy and users' ages. FDA found the study to be limited in how well it can determine the effects of benzoyl peroxide over long periods for persons who have greater exposure in locations where the sun is more intense than in Canada.

Benzoyl peroxide continues to be available over the counter and by prescription in a number of strengths while researchers perform the additional studies. FDA considers benzoyl peroxide safe for treating acne while tests proceed.

The proposed warning is in two parts:

In boldface type as the first sentence under the "Warnings" heading is the statement: "When using this product, avoid unnecessary sun exposure and use a sunscreen."
In the "Directions" section of the labeling is the statement: "If going outside, use a sunscreen [the preceding sentence is in boldface type]. Allow (product name) to dry, then follow directions in the sunscreen labeling. If irritation or sensitivity develops, discontinue use of both products and consult a doctor."
Under FDA's proposal, manufacturers would put the new labeling on boxes or inserts for OTC products. Prescription acne treatments containing benzoyl peroxide would have the labeling in patient package inserts.

Benzoyl peroxide is found in more than a dozen OTC medications. Among them: Acne 10, Benoxyl 10, Clear By Design, Clearasil B.P., Fostex 10% BPO, Loxoide, Nutrogena Acne Mask, Noxzema Clear Up Acne Medicated Maximum Strength, Oxy-10, Oxy-5, Pan Oxyl 10 bar, Vanoxide .5%, and Zerac BP10.

FDA's concerns involve only benzoyl peroxide-based products. They do not apply to other OTC acne formulations, including:

Sulfur--Xerac-4% gel, Acne-Aid 10% lotion, Fostex Medicated Cover-Up Cream, Sulray 10% bar, and Cuticura ointment.
Sulfur/salicylic acid--Aveenobar, Klaron lotion, Pernox Regular cleanser, and Sastid soap.
Sulfur/resorcinol--Acnomel cream, Rezamid lotion, pHisoAc cream, and Clearasil Adult Care.
Salicylic acid--Dry & Clear cleanser 0.5%, Listerex Herbal Lotion, Saligel 5%, AquaGlyde cleanser, and Stri-Dex Maximum Strength Pads.
Acne's Origins
Acne starts when glands in hair canals (follicles) just below the skin's surface make an oily substance called sebum. Normally, sebum empties through follicle openings onto the skin surface, where it is washed away. In people of both sexes who get acne, the adrenal glands secrete male-type hormones that trigger excess production of sebum. Experts believe sebum stimulates the lining of the follicle wall, causing cells to shed, stick together, and plug up the follicle opening. If this plug remains below the surface, it is usually light in color and called a whitehead, or closed comedo. An enlarged plug that emerges from the follicle typically has a dark tip and is called a blackhead (an open comedo). The mixture of cells and oil creates a breeding ground for bacteria, which produce chemicals that can break down the follicle wall and create pimples or more serious inflammation.

OTC drugs work in similar ways. Benzoyl peroxide, resorcinol, salicylic acid, and sulfur are all "peeling agents," technically known as keratolytics. They cause a superficial irritation and drying that helps the body loosen plugs in the follicle and slough off dead cells. These drugs also keep bacteria from forming in the follicle. This, in turn, reduces fatty acids that contribute to plugs. A number of OTC acne drug products combine sulfur with resorcinol.

In severe acne cases, doctors prescribe other drugs either separately or in tandem with OTC preparations.

The American Academy of Dermatology cautions against scratching or squeezing acne sores, which can lead to more inflammation and scarring. The academy offers a free brochure about acne and its treatment. For a copy, send a stamped, business-size envelope to: American Academy of Dermatology P.O. Box 681069 Schaumburg, IL 60168-1069

FDA's proposed labeling changes on benzoyl peroxide products warn users to avoid unnecessary sun exposure and to apply a sunscreen if going outdoors.

That's Oil, Folks!
Sebaceous glands in hair canals (follicles) produce an oily substance called sebum. Normally, sebum empties onto the skin surface and is washed away. But sometimes hormones produced in the adrenal glands trigger production of excess sebum, which creates plugs in follicle openings. If the plug breaks through the skin, appearing darker than the skin, it is called a blackhead, or open comedo. If the plug is below the skin surface, it is called a whitehead, or closed comedo.

ILLUSTRATION: Two boys having skin problems.

PHOTOS (BLACK & WHITE): ZITS!

ILLUSTRATION: Open Comedo

ILLUSTRATION: Closed Comedo

~~~~~~~~

By John Henkel

John Henkel is a staff writer for FDA Consumer.

Share this with your friends