Antiacne Drugs

Definition

Antiacne drugs are medicines that help clear up pimples, blackheads, whiteheads, and more severe forms of acne.

Purpose

Different types of antiacne drugs are used for different purposes. For example, lotions, soaps, gels, and creams containing benzoyl peroxide or tretinoin may be used to clear up mild to moderately severe acne. Isotretinoin (Accutane) is prescribed only for very severe, disfiguring acne.

Acne is a skin condition that occurs when pores or hair follicles become blocked. This blockage allows a waxy material called sebum to collect inside the pores or follicles. Normally, sebum flows out onto the skin and hair to form a protective coating, but when it cannot get out, small swellings develop on the skin surface. Bacteria and dead skin cells can also collect that can cause inflammation. Swellings that are small and not inflamed are whiteheads or blackheads. When they become inflamed, they turn into pimples. Pimples that fill with pus are called pustules.

The severity of acne is often influenced by seasonal changes; it is typically less severe in summer than in winter. In addition, acne in girls is often affected by the menstrual cycle.

Acne cannot be cured, but acne drugs can help clear the skin. Benzoyl peroxide and tretinoin work by mildly irritating the skin. This encourages skin cells to slough off, which helps open blocked pores. Benzoyl peroxide also kills bacteria, which helps prevent whiteheads and blackheads from turning into pimples. Isotretinoin shrinks the glands that produce sebum.

Description

Benzoyl peroxide is found in many over-the-counter acne products that are applied to the skin, such as Benoxyl, Clear By Design, Neutrogena Acne, PanOxyl, and some formulations of Clean & Clear, Clearasil, and Oxy. Some benzoyl peroxide products are available without a physician's prescription; others require a prescription. Tretinoin (Retin-A) is available only with a physician's prescription and comes in liquid, cream, and gel forms, which are applied to the skin. Isotretinoin (Accutane), which is taken by mouth in capsule form, is available only with a physician's prescription. Only physicians who have experience in diagnosing and treating severe acne, such as dermatologists, should prescribe isotretinoin.

Some newer antiacne preparations combine benzoyl peroxide with antibiotics. One combination of benzoyl peroxide with clindamycin is sold under the trade name BenzaClin.

Many antiacne preparations contain compounds derived from plants that have anti-inflammatory properties. One group of researchers listed thirtyeight different plants that are beneficial in treating acne and other inflammatory skin conditions.

Recommended dosage

The recommended dosage depends on the type of antiacne drug. These drugs usually come with written directions for patients and should be used only as directed. Patients who have questions about how to use the medicine should check with a physician or pharmacist.

KEY TERMS

Acne— A skin condition in which raised bumps, pimples, and cysts form on the face, neck, shoulders and upper back.

Bacteria— Tiny, one-celled forms of life that cause many diseases and infections.

Bowel— The intestine; a tube-like structure that extends from the stomach to the anus. Some digestive processes are carried out in the bowel before food passes out of the body as waste.

Cyst— An abnormal sac or enclosed cavity in the body, filled with liquid or partially solid material.

Dermatologist— A doctor who specializes in treating diseases and disorders of the skin.

Eczema— Inflammation of the skin with itching and a rash. The rash may have blisters that ooze and form crusts.

Pimple— A small, red swelling of the skin.

Psoriasis— A skin disease in which people have itchy, scaly, red patches on the skin.

Pus— Thick, whitish or yellowish fluid that forms in infected tissue.

Triglyceride— A substance formed in the body from fat in the diet.

Patients who use isotretinoin usually take the medicine for a few months, then stop for at least two months. Their acne may continue to improve even after they stop taking the medicine. If the condition is still severe after several months of treatment and a two-month break, the physician may prescribe a second course of treatment.

Precautions

Isotretinoin

Isotretinoin can cause serious birth defects, including mental retardation and physical deformities. This medicine should not be used during pregnancy. Women who are able to bear children should not use isotretinoin unless they have very severe acne that has not cleared up with the use of other antiacne drugs. In that case, a woman who uses this drug must have a pregnancy test two weeks before beginning treatment and each month they are taking the drug. Another pregnancy test must be done one month after treatment ends. The woman must use an effective birth control method for one month before treatment begins and must continue using it throughout treatment and for one month after treatment ends. Women who are able to bear children and who want to use this medicine should discuss this information with their health care providers. Before using the medicine, they will be asked to sign a consent form stating that they understand the danger of taking isotretinoin during pregnancy and that they agree to use effective birth control.

Do not donate blood to a blood bank while taking isotretinoin or for 30 days after treatment with the drug ends. This will help reduce the chance of a pregnant woman receiving blood containing isotretinoin, which could cause birth defects.

Isotretinoin may cause a sudden decrease in night vision. If this happens, do not drive or do anything else that could be dangerous until vision returns to normal. Let the physician know about the problem.

This medicine may also make the eyes, nose, and mouth dry. Ask the physician about using special eye drops to relieve eye dryness. To temporarily relieve the dry mouth, chew sugarless gum, suck on sugarless candy or ice chips, or use saliva substitutes, which come in liquid and tablet forms and are available without a prescription. If the problem continues for more than two weeks, check with a physician or dentist. Mouth dryness that continues over a long time may contribute to tooth decay and other dental problems.

Isotretinoin may increase sensitivity to sunlight. Patients being treated with this medicine should avoid exposure to the sun and should not use tanning beds, tanning booths, or sunlamps until they know how the drug affects them.

In the early stages of treatment with isotretinoin, some people's acne seems to get worse before it starts getting better. If the condition becomes much worse or if the skin is very irritated, check with the physician who prescribed the medicine.

Benzoyl peroxide and tretinoin

When applying antiacne drugs to the skin, be careful not to get the medicine in the eyes, mouth, or inside of the nose. Do not put the medicine on skin that is wind burned, sunburned, or irritated, and do not apply it to open wounds.

Because such antiacne drugs as benzoyl peroxide and tretinoin irritate the skin slightly, avoid doing anything that might cause further irritation. Wash the face with mild soap and water only two or three times a day, unless the physician says to wash it more often. Avoid using abrasive soaps or cleansers and products that might dry the skin or make it peel, such as medicated cosmetics, cleansers that contain alcohol, or other acne products that contain resorcinol, sulfur or salicylic acid.

If benzoyl peroxide or tretinoin make the skin too red or too dry or cause too much peeling, check with a physician. Using the medicine less often or using a weaker strength may be necessary.

Tretinoin may increase sensitivity to sunlight. While being treated with this medicine, avoid exposure to the sun and do not use tanning beds, tanning booths, or sunlamps. If it is not possible to avoid being in the sun, use a sunscreen with a skin protection factor (SPF) of at least 15 or wear protective clothing over the treated areas. The skin may also become more sensitive to cold and wind. People who use this medicine should protect their skin from cold and wind until they know how the medicine affects them.

Benzoyl peroxide may discolor hair or colored fabrics.

Special conditions

People who have certain medical conditions or who are taking certain other medicines may have problems if they use antiacne drugs. Before using these products, be sure to let the physician know about any of these conditions:

ALLERGIES. Anyone who has had unusual reactions to etretinate, isotretinoin, tretinoin, vitamin A preparations, or benzoyl peroxide in the past should let his or her physician know before using an antiacne drug. The physician should also be told about any allergies to foods, dyes, preservatives, or other substances.

PREGNANCY. Women who are pregnant or who may become pregnant should check with a physician before using tretinoin or benzoyl peroxide. Isotretinoin causes birth defects in humans and must not be used during pregnancy.

BREASTFEEDING. No problems have been reported in nursing babies whose mothers used tretinoin or benzoyl peroxide. Women who are breastfeeding babies should not take isotretinoin, however, as it may cause problems in nursing babies.

OTHER MEDICAL CONDITIONS. Before using antiacne drugs applied to the skin, people with any of these medical problems should make sure their physicians are aware of their conditions:

• eczema. Antiacne drugs that are applied to the skin may make this condition worse.
• sunburn or raw skin. Antiacne drugs that are applied to the skin may increase the pain and irritation of these conditions.

In people with certain medical conditions, isotretinoin may increase the amount of triglyceride (a fatty-substance) in the blood. This may lead to heart or blood vessel problems. Before using isotretinoin, people with any of these medical problems should make sure their physicians are aware of their conditions:

• alcoholism or heavy drinking, now or in the past
• diabetes (or family history of diabetes). Isotretinoin may also change blood sugar levels.
• family history of high triglyceride levels in the blood
• severe weight problems.

USE OF CERTAIN MEDICINES. Using antiacne drugs with certain other drugs may affect the way the drugs work or may increase the chance of side effects.

Side effects

Isotretinoin

Minor discomforts such as dry mouth or nose, dry eyes, dry skin, or itching usually go away as the body adjusts to the drug and do not require medical attention unless they continue or are bothersome.

Other side effects should be brought to a physicians attention. These include:

• burning, redness, or itching of the eyes
• nosebleeds
• signs of inflammation of the lips, such as peeling, burning, redness or pain

Bowel inflammation is not a common side effect, but it may occur. If any of the following signs of bowel inflammation occur, stop taking isotretinoin immediately and check with a physician:

• pain in the abdomen
• bleeding from the rectum
• severe diarrhea

Benzoyl peroxide and tretinoin

The most common side effects of antiacne drugs applied to the skin are slight redness, dryness, peeling, and stinging, and a warm feeling to the skin. These problems usually go away as the body adjusts to the drug and do not require medical treatment.

Other side effects should be brought to a physician's attention. Check with a physician as soon as possible if any of the following side effects occur:

• blistering, crusting or swelling of the skin
• severe burning or redness of the skin
• darkening or lightening of the skin. (This effect will eventually go away after treatment with an antiacne drug ends.)
• skin rash

Other side effects are possible with any type of antiacne drug. Anyone who has unusual symptoms while using antiacne drugs should get in touch with his or her physician.

Interactions

Patients using antiacne drugs on their skin should tell their physicians if they are using any other prescription or nonprescription (over-the-counter) medicine that they apply to the skin in the same area.

Isotretinoin may interact with other medicines. When this happens, the effects of one or both drugs may change or the risk of side effects may be greater. Anyone who takes isotretinoin should let the physician know about all other medicines he or she is taking and should ask whether the possible interactions can interfere with drug therapy. Among the drugs that may interact with isotretinoin are:

• etretinate (Tegison), used to treat severe psoriasis. Using this medicine with isotretinoin increases side effects.
• tretinoin (Retin-A, Renova). Using this medicine with isotretinoin increases side effects.

• vitamin A or any medicine containing vitamin A. Using any vitamin A preparations with isotretinoin increases side effects. Do not take vitamin supplements containing vitamin A while taking isotretinoin.
• tetracyclines (used to treat infections). Using these medicines with isotretinoin increases the chance of swelling of the brain. Make sure the physician knows if tetracycline is being used to treat acne or another infection.

Resources

BOOKS

Beers, Mark H., MD, and Robert Berkow, MD., editors. "Acne." Section 10, Chapter 116 In The Merck Manual of Diagnosis and Therapy. Whitehouse Station, NJ: Merck Research Laboratories, 2002.

Beers, Mark H., MD, and Robert Berkow, MD., editors. "Warts (Verrucae)." Section 10, Chapter 115 In The Merck Manual of Diagnosis and Therapy. Whitehouse Station, NJ: Merck Research Laboratories, 2002.

Wilson, Billie Ann, Margaret T. Shannon, and Carolyn L. Stang. Nurse's Drug Guide 2003. Upper Saddle River, NJ: Prentice Hall, 2003.

PERIODICALS

Breneman, D., R. Savin, C. Van dePol, et al. "Double-Blind, Randomized, Vehicle-Controlled Clinical Trial of Once-Daily Benzoyl Peroxide/Clindamycin Topical Gel in the Treatment of Patients with Moderate to Severe Rosacea." International Journal of Dermatology 43 (May 2004): 381-387.

Darshan, S., and R. Doreswamy. "Patented Antiinflammatory Plant Drug Development from Traditional Medicine." Phytotherapy Research 18 (May 2004): 343-357.

Halder, R. M., and G. M. Richards. "Topical Agents Used in the Management of Hyperpigmentation." Skin Therapy Letter 9 (June-July 2004): 1-3.

Kligman, D. E., and Z. D. Draelos. "High-Strength Tretinoin for Rapid Retinization of Photoaged Facial Skin." Dermatologic Surgery 30 (June 2004): 864-866.

Leyden, J. J., D. Thiboutot, and A. Shalita. "Photographic Review of Results from a Clinical Study Comparing Benzoyl Peroxide 5%/Clindamycin 1% Topical Gel with Vehicle in the Treatment of Rosacea." Cutis 73, Supplement 6 (June 2004): 11-17.

ORGANIZATIONS

American Academy of Dermatology (AAD). P. O. Box 4014, Schaumburg, IL 60168-4014. (847) 330-0230. 〈http://www.aad.org.〉.

American Society of Health-System Pharmacists (ASHP). 7272 Wisconsin Avenue, Bethesda, MD 20814. (301) 657-3000. 〈http://www.ashp.org〉.

United States Food and Drug Administration (FDA). 5600 Fishers Lane, Rockville, MD 20857-0001. (888) INFO-FDA. 〈http://www.fda.gov〉.

Antiacne drugs

Definition

Acne is a skin disorder that leads to an outbreak of lesions called pimples or "zits." The most common form of the disease in adolescents is called acne vulgaris. Antiacne drugs are the medicines that help clear up the pimples, blackheads, whiteheads, and more severe forms of lesions that occur when a teen has acne.

Different types of antiacne drugs are used for different treatment purposes, depending on the severity of the condition. For example, lotions, soaps, gels, and creams containing substances called benzoyl peroxide or tretinoin may be used to clear up mild to moderately severe acne. Isotretinoin (Accutane) is an oral drug that is prescribed only for very severe, disfiguring acne.

Acne is caused by the overproduction of sebum during puberty when high levels of the male hormone androgen cause excess sebum to form. Sebum is an oily substance that forms in glands just under the surface of the skin called sebaceous glands. Sebum normally flows out hair follicles onto the skin to act as a natural skin moisturizer. The glands are connected to hair follicles that allow the sebum, or oil, to empty onto the skin through a pore.

Sometimes the sebum combines with dead, sticky skin cells and bacteria called Propionibacterium acnes (P. acnes) that normally live on the skin. The mixture of oil and cells allows the bacteria to grow in the follicles. When this happens, a hard plug called a comedo can form. A comedo is an enlarged hair follicle. It can appear on the skin as a blackhead, which is a comedo that reaches the skin's surface and looks black, or as a whitehead, which is a comedo that is sealed by keratin, the fibrous protein produced by the skin cells and looks like a white bump.

In addition, pimples can form on the skin. Types of pimples include:

• papules, which are small, red bumps that may be tender to touch
• pustules, which are pus-filled lesions that are often red at the base
• nodules, which are large, painful lesions deep in the skin
• cysts, which are painful pus-filled lesions deep in the skin that can cause scarring

Pimples form when the follicle is invaded by the P. acnes bacteria. The damaged follicle weakens and bursts open, releasing sebum, bacteria, skin cells, and white blood cells into surrounding tissues. Scarring happens when new skin cells are created to replace the damaged cells. The most severe type of acne includes both nodules and cysts.

Description

Acne cannot be cured, but antiacne drugs can help clear the skin and reduce the chance of scarring. The goal of treating moderate acne is to decrease inflammation and prevent new comedones from forming. Benzoyl peroxide and tretinoin work by mildly irritating the skin. This encourages skin cells to slough off, which helps open blocked pores. Benzoyl peroxide also kills bacteria, which helps prevent whiteheads and blackheads from turning into pimples. Isotretinoin shrinks the glands that produce sebum. It is used for severe acne lesions and must be carefully monitored because of its side effects. Antibiotics also may be prescribed to kill bacteria and reduce inflammation.

General use

Benzoyl peroxide is found in many over-the-counter acne products that are applied to the skin, such as Benoxyl, Neutrogena Acne, PanOxyl, and some formulations of Clean & Clear, Clearasil, and Oxy. Some benzoyl peroxide products are available without a physician's prescription; others require a prescription. Acne treatments that can dry the skin should be used with caution by people with skin of color.

Tretinoin (Retin-A) is available only with a physician's prescription. It comes in liquid, cream, and gel forms, which are applied to the skin. Isotretinoin (Accutane), which is taken by mouth in capsule form, is available only with a physician's prescription. Only physicians experienced in diagnosing and treating severe acne, such as dermatologists, should prescribe isotretinoin.

Recommended dosages

The recommended dosage depends on the type of antiacne drug. These drugs usually come with written directions for patients and should be used only as directed by the prescribing physician. Teens who have questions about how to use the medicine should check with their physician or pharmacist.

Patients who use isotretinoin usually take the medicine for a few months, then stop for at least two months. Their acne may continue to improve even after they stop taking the medicine. If the condition is still severe after several months of treatment and a two-month break, the physician may prescribe a second course of treatment.

Precautions

Isotretinoin

Isotretinoin can cause serious birth defects, including mental retardation and physical deformities. This medicine should not be used during pregnancy. Females who are able to bear children should not use isotretinoin unless they have very severe acne that has not cleared up with the use of other antiacne drugs. In that case, a woman who uses this drug must have a pregnancy test two weeks before beginning treatment and each month she is taking the drug. Another pregnancy test must be done one month after treatment ends. The woman must use an effective birth control method for one month before treatment begins and must continue using it throughout treatment and for one month after treatment ends. Females who are able to bear children and who want to use this medicine should discuss this information with their healthcare providers. Before using the medicine, they will be asked to sign a consent form stating that they understand the danger of taking isotretinoin during pregnancy and that they agree to use effective birth control.

People using this drug should not donate blood to a blood bank while taking isotretinoin or for 30 days after treatment with the drug ends. This will help reduce the chance of a pregnant woman receiving blood containing isotretinoin, which could cause birth defects.

Isotretinoin may cause a sudden decrease in night vision. If this happens, users should not drive or do anything else that could be dangerous until vision returns to normal. They should also let the physician know about the problem.

This medicine may also make the eyes, nose, and mouth dry. Ask the physician about using special eye drops to relieve eye dryness. To temporarily relieve the dry mouth, chew sugarless gum, suck on sugarless candy or ice chips, or use saliva substitutes, which come in liquid and tablet forms and are available without a prescription. If the problem continues for more than two weeks, check with a physician or dentist. Mouth dryness that continues over a long time may contribute to tooth decay and other dental problems.

Isotretinoin may increase sensitivity to sunlight. Patients being treated with this medicine should avoid exposure to the sun and should not use tanning beds, tanning booths, or sunlamps until they know how the drug affects them.

In the early stages of treatment with isotretinoin, some people's acne seems to get worse before it starts getting better. If the condition becomes much worse or if the skin is very irritated, they should check with the physician who prescribed the medicine.

Benzoyl peroxide and tretinoin

When applying antiacne drugs to the skin, people should be careful not to get the medicine in the eyes, mouth, or inside the nose. They should not put the medicine on skin that is wind burned, sunburned, or irritated, and not apply it to open wounds .

Because antiacne drugs such as benzoyl peroxide and tretinoin irritate the skin slightly, users should avoid doing anything that might cause further irritation. They should wash the face with mild soap and water only two or three times a day, unless the physician says to wash it more often. They should also avoid using abrasive soaps or cleansers and products that might dry the skin or make it peel, such as medicated cosmetics, cleansers that contain alcohol, or other acne products that contain resorcinol, sulfur, or salicylic acid.

If benzoyl peroxide or tretinoin make the skin too red or too dry or cause too much peeling, the user should check with a physician. Using the medicine less often or using a weaker strength may be necessary. Benzoyl peroxide can irritate the skin of people with skin of color and cause darkened spots called hyperpigmentation on the skin. Benzoyl peroxide may discolor hair or colored fabrics.

ORAL DRUGS Oral antibiotics are taken daily for two to four months. The drugs used include tetracycline, erythromycin, minocycline (Minocin), doxycycline, clindamycin (Cleocin), and trimethoprim-sulfamethoxazole (Bactrim, Septra). Possible side effects include allergic reactions, stomach upset, vaginal yeast infections, dizziness , and tooth discoloration.

The goal of treating moderate acne is to decrease inflammation and prevent new comedones from forming. One effective treatment is topical tretinoin, used along with a topical or oral antibiotic. A combination of topical benzoyl peroxide and erythromycin is also very effective. Improvement is normally seen within four to six weeks, but treatment is maintained for at least two to four months.

Special conditions

People who have certain medical conditions or who are taking certain other medicines may have problems if they use antiacne drugs. Before using these products, the physician should be informed about any of the following conditions.

ALLERGIES Anyone who has had unusual reactions to etretinate, isotretinoin, tretinoin, vitamin A preparations, or benzoyl peroxide in the past should let the physician know before using an antiacne drug. The physician should also be told about any allergies to foods, dyes, preservatives, or other substances.

PREGNANCY Teens who are pregnant or who may become pregnant should check with a physician before using tretinoin or benzoyl peroxide. Isotretinoin causes birth defects in humans and must not be used during pregnancy.

OTHER MEDICAL CONDITIONS Before using antiacne drugs applied to the skin, people with any of these medical problems should make sure their physicians are aware of their conditions:

• Eczema. Antiacne drugs that are applied to the skin may make this condition worse.
• Sunburn or raw skin. Antiacne drugs that are applied to the skin may increase the pain and irritation of these conditions.

In people with certain medical conditions, isotretinoin may increase the amount of triglyceride (a fatty-substance) in the blood. This may lead to heart or blood vessel problems. Before using isotretinoin, adolescents with any of the following medical problems should make sure their physicians are aware of their conditions:

• alcoholism or heavy drinking, currently or in the past
• diabetes or family history of diabetes (Isotretinoin may change blood sugar levels.)
• family history of high triglyceride levels in the blood
• severe weight problems

Using antiacne drugs with certain other drugs may affect the way the drugs work or may increase the chance of side effects.

Side effects

Conditions caused by isotretinoin

Minor discomforts such as dry mouth or nose, dry eyes, dry skin, or itching usually go away as the body adjusts to the drug and do not require medical attention unless they continue or are bothersome.

Other side effects should be brought to a physician's attention. These include:

• burning, redness, or itching of the eyes
• nosebleeds
• signs of inflammation of the lips, such as peeling, burning, redness or pain

Bowel inflammation is not a common side effect, but it may occur. If any of the following signs of bowel inflammation occur, stop taking isotretinoin immediately and check with a physician:

• pain in the abdomen
• bleeding from the rectum
• severe diarrhea

Conditions caused by benzoyl peroxide and tretinoin

The most common side effects of antiacne drugs applied to the skin are slight redness, dryness, peeling, and stinging, and a warm feeling to the skin. These problems usually go away as the body adjusts to the drug and do not require medical treatment.

Other side effects should be brought to a physician's attention. Check with a physician as soon as possible if any of the following side effects occur:

• blistering, crusting, or swelling of the skin
• severe burning or redness of the skin>
• darkening or lightening of the skin (This effect will eventually go away after treatment with an antiacne drug ends.)
• skin rash

Other side effects are possible with any type of antiacne drug. Anyone who has unusual symptoms while using antiacne drugs should get in touch with his or her physician.

Interactions

Patients using antiacne drugs on their skin should tell their physicians if they are using any other prescription or nonprescription (over-the-counter) medicine that they apply to the skin in the same area as the antiacne drug.

Isotretinoin may interact with other medicines. When this happens, the effects of one or both drugs may change or the risk of side effects may be greater. Anyone who takes isotretinoin should let the physician know about all other medicines being used and should ask whether the possible interactions can interfere with drug therapy. Among the drugs that may interact with isotretinoin are listed below:

• Etretinate (Tegison), used to treat severe psoriasis . Using this medicine with isotretinoin increases side effects.
• Tretinoin (Retin-A, Renova). Using this medicine with isotretinoin increases side effects.
• Vitamin A or any medicine containing vitamin A. Using any vitamin A preparations with isotretinoin increases side effects. Do not take vitamin supplements containing vitamin A while taking isotretinoin.
• Tetracyclines (used to treat infections). Using these medicines with isotretinoin increases the chance of swelling of the brain. Make sure the physician knows if tetracycline is being used to treat acne or another infection.

KEY TERMS

Acne —A chronic inflammation of the sebaceous glands that manifests as blackheads, whiteheads, and/or pustules on the face or trunk.

Bacteria —Singular, bacterium; tiny, one-celled forms of life that cause many diseases and infections.

Bowel —The intestine; a tube-like structure that extends from the stomach to the anus. Some digestive processes are carried out in the bowel before food passes out of the body as waste.

Cyst —An abnormal sac or enclosed cavity in the body filled with liquid or partially solid material. Also refers to a protective, walled-off capsule in which an organism lies dormant.

Eczema —A superficial type of inflammation of the skin that may be very itchy and weeping in the early stages; later, the affected skin becomes crusted, scaly, and thick.

Noncomedogenic —A substance that does not contribute to the formation of blackheads or pimples on the skin. Jojoba oil is noncomedogenic.

Pimple —A small, red swelling of the skin.

Psoriasis —A chronic, noncontagious skin disease that is marked by dry, scaly, and silvery patches of skin that appear in a variety of sizes and locations on the body.

Pus —A thick, yellowish or greenish fluid composed of the remains of dead white blood cells, pathogens, and decomposed cellular debris. It is most often associated with bacterial infection.

Triglyceride —A substance formed in the body from fat in the diet. Triglycerides are the main fatty materials in the blood. Bound to protein, they make up high- and low-density lipoproteins (HDLs and LDLs). Triglyceride levels are important in the diagnosis and treatment of many diseases including high blood pressure, diabetes, and heart disease.

Parental concerns

Acne comes at a difficult time, the adolescent years. While mild acne can be treated with over-the-counter medications, more severe acne needs medical attention. Experts advise against a wait-and-see attitude. Treatment options can help control acne and avoid scarring.

Isotretinoin can cause serious birth defects, including mental retardation and physical deformities. This medicine should not be used during pregnancy. Sexually active adolescent females who are able to bear children should not use isotretinoin unless they have very severe acne that has not cleared up with the use of other antiacne drugs. In addition, acne treatments that can dry the skin should be used with caution by people with skin of color.

See also Acne.

Resources

BOOKS

McNally, Robert A. Skin Health Information for Teens: Health Tips about Dermatological Concerns and Skin Cancer Risks. Detroit, MI: Omnigraphics, 2003.

Simons, Rae. For All to See: A Teen's Guide to Healthy Skin. Broomall, PA: Mason Crest, 2005.

ORGANIZATIONS

American Academy of Dermatology. 930 E. Woodfield Rd., Schaumburg, IL 60168. Web site: <www.aad.org/pamphlets/acnepamp.html>.

WEB SITES

"Accutane." American Osteopathic College of Dermatology. Available online at <http://aocd.org/skin/dermatologic_diseases/accutane.html> (accessed October 16, 2004).

"Questions and Answers about Acne." National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) Information Clearinghouse, October 2001. Available online at <www.niams.nih.gov/hi/topics/acne/acne.htm> (accessed October 16, 2003).

"Treating Acne in Skin of Color." AcneNet, 2002. Available online at <www.skincarephysicians.com/acnenet/update.htm> (accessed October 16, 2004).

"'What Can I Do about Pimples?"' American Family Physician, Information from Your Family Doctor Handout, January 15, 2000. Available online at <www.aafp.org/afp/20000115/20000115a.html> (accessed October 15, 2004).

Christine Kuehn Kelly

Acne Medication

Acne is a skin condition in which pimples (comedones) appear on the skin, usually on the face, chest, or back. Adolescents and young adults are most often afflicted. Acne tends to be more severe in males; however, with females, acne may persist into adulthood.

Causes and Types of Acne

The skin has hair follicles that each contains a hair shaft and an oil gland. The oil glands continuously produce and secrete oil to lubricate and protect the skin. However, when dead skin cells and oil (sebum) build up inside the follicle and close off the follicle's pore, pimples appear, in the form of either blackheads or whiteheads. If the plugging material protrudes from the opening at the surface of the skin, this plug of oil and dead cells darkens, forming blackheads; if the plugging material does not protrude, whiteheads form. This type of acne is referred to as comedonal. When the accumulated material of a closed-off pimple causes the follicular wall to rupture, an internal inflammatory reaction occurs, causing oil, dead cells, and bacteria to spill onto the skin. The skin around the pore becomes red and inflamed, and the result is inflammatory acne. When white blood cells infiltrate the area to repair the inflammation, papules, nodules, and cysts may develop. Papules form near the surface of the skin, whereas nodules and cysts are caused by inflammation deeper in the skin.

In the past many persons attributed abnormally high oil secretion and the development of acne to the afflicted individual's diet and hygiene. However, current research suggests that oil secretion is under genetic control, primarily related to the ability of androgenic hormones to stimulate oil secretion. The bacterial species Propionibacterium acnes is believed to play a role in converting acne into an inflammatory condition. Stress and the use of certain cosmetics may also be contributing factors.

Treatment of Acne

There are many ways to treat acne. Gentle washing of the face is important because it helps to remove accumulated oil, bacteria, and dead cells on the skin's surface. Other treatments help to unclog pores, kill bacteria, or minimize oil. Products that help to open up pores include mild cleansers, scrubs, exfoliants, and masques. All of these are available without a prescription. Exfoliants remove the outer layer of skin, thus opening pores. These agents, as well as astringents and toners, help to wipe away excess oil. Antibacterial agents are used to kill bacteria. The most common mild antibacterial agent is benzoyl peroxide. It is available in the form of creams or lotions that are applied to affected areas, and may even be found in some cleansers. Other antibacterial agents available by prescription include topical antibiotics such as erythromycin , clindamycin, and sulfacetamide, and oral antibiotics such as tetracycline, doxycycline, minocycline, and sulfa drugs.

Benzoyl peroxide. Benzoyl peroxide encourages peeling of the outermost layer of the skin and, as mentioned previously, is a mild bactericidal agent. It kills bacteria by virtue of its oxidizing properties. It is often included in prescription acne medications, and in nonprescription acne products such as gels, lotions, and cleansers. It may be used alone or with other treatments. At even low concentrations (2.5–10%), benzoyl peroxide diminishes the population of Propionibacterium acnes. The most common adverse effects are dry skin and bleaching of the skin.

Retinoids. The term "retinoid" refers to retinol or other closely related derivatives, either natural or synthetic. Retinoids may or may not have retinol-like (vitamin A–like) activity. Retinoids affect epithelial cells by binding to receptors inside these cells, inducing alterations in the transcription of genes. Retinoids enhance the synthesis of some proteins, such as proteins that serve as receptors for certain hormones and growth factors, and reduce the synthesis of others. Some of the most commonly prescribed treatments for acne—tretinoin, isotretinoin, and adapalene—are retinoids. (See Table 1.)

Tretinoin became available as a topical treatment for acne in the United States in 1971. Tretinoin is also known by its chemical name, all-trans -retinoic acid. It increases the turnover of skin cells at the surface of the hair follicle. This leads to the extrusion of comedones. Side effects include local skin irritation and increased sun sensitivity. Newer preparations of tretinoin, designed to achieve slow absorption of the drug into epithelial cells, cause less skin irritation than forms available initially. Improvement in acne may not be noticeable until two to three weeks after treatment begins.

In 1982 the Food and Drug Administration (FDA) approved the oral use of isotretinoin (Accutane) for the treatment of severe nodulocystic acne that has not responded to antibiotics. This drug is not active topically. As the name suggests, isotretinoin is an isomer of tretinoin. The only structural difference between the two molecules lies in the spatial arrangement of the atoms around one carbon-carbon double bond. Isotretinoin has the chemical name 13-cis -retinoic acid. Through mechanisms not well understood, it decreases the size of the sebaceous glands and inhibits closure of the pore. These actions may diminish the ultimate formation of cysts. As is

the case with other retinoids, arachidonic acid release from macrophages is inhibited. This may account for the anti-inflammatory effects of retinoids. Isotretinoin's anti-acne effects can last for months to years following a twenty week course. And, unlike antibiotic treatments, treatment with isotretinoin does not promote antibiotic-resistant bacteria.

Reservations toward the use of isotretinoin (Accutane) are related to its severe side effects. Any of the retinoids, including vitamin A, can have severe side effects. Some of the symptoms of hypervitaminosis A are the same as the major toxic effects associated with the therapeutic use of retinoids. When retinoids are applied to the skin, few systemic side effects occur. For isotretinoin, which is administered orally, side effects are much more common. Among those reported are skin blistering, skin fragility, hair loss, headache, nausea, vomiting, visual disturbances, and increased levels of triglycerides and decreased levels of high density lipoproteins in blood plasma. Furthermore, because isotretinoin can cause severe birth defects, including physical abnormalities and mental retardation, a female patient taking it must not become pregnant. Female patients must obtain a negative serum pregnancy test before treatment can begin, and written consent forms must be signed. These patients should also not become pregnant for some time after the drug has been discontinued. In 1998, as a result of medical reports associating Accutane use with depression and suicide, the FDA issued new safety information regarding isotretinoin.

Newer retinoids. Medical chemists are often able to modify the structure of a drug that has unwanted side effects or problems making it difficult to administer. Even slight structural changes may result in an improved pharmacological agent that requires lower dosing, or has fewer side effects, or both. The development of adapalene is an example. A better retinoid might have enhanced stability, enhanced anti-inflammatory effects, or result in decreased skin irritation. The naphthoic-acid derivative adapalene, developed in the 1990s, works better and with less local skin irritation than earlier retinoids. The reduced side effects are attributed to the selectivity of adapalene for nuclear retinoic acid receptors within follicular epithelial cells. Although many persons will have acne during their teen years, effective treatment is available.

see also Retinol.

Jennifer L. Powers

Bibliography

Bershad, Susan V. (2001). "The Modern Age of Acne Therapy: A Review of Current Treatment Options." The Mount Sinai Journal of Medicine 68(4–5):279–286. Full text also available from <http://www.mssm.edu/msjournal>.

Internet Resources

Information available from <http://www.accutaneaction.com>.

Information available from <http://www.differin.com>.

Information available from <http://www.fda.gov>.

Information available from <http://healthsquare.com/drugmain.htm>.