Medical Questions

Skin Care

What Is Acne?

Acne is a disorder of the skin's oil glands (sebaceous glands) that results in plugged pores and outbreaks of lesions commonly called pimples or zits. Acne lesions usually occur on the face, neck, back, chest, and shoulders. Nearly 17 million people in the United States have acne, making it the most common skin disease. Although acne is not a serious health threat, severe acne can lead to disfiguring, permanent scarring, which can be upsetting for people who suffer from the disorder. 

How Does Acne Develop?
 
Doctors describe acne as a disease of the pilosebaceous units. Found over most of the body, pilosebaceous units consist of a sebaceous (oil) gland connected to a hair-containing canal called a follicle (see figure 1). These units are largest and most numerous on the face, upper back, and chest -- areas where acne tends to occur. The sebaceous glands make an oily substance called sebum that normally empties onto the skin surface through the opening of the follicle.

Acne is believed to result from a change in the inner lining of the follicle that prevents the sebum from passing through. For reasons not understood, cells from the lining of the follicle are shed too fast and clump together. The clumped cells plug up the follicle's opening so sebum cannot reach the surface of the skin. The mixture of oil and cells causes bacteria that normally live on the skin, called Propionibacterium acnes (P. acnes), to grow in the plugged follicles. These bacteria produce chemicals and enzymes that can cause inflammation. (Inflammation is a characteristic reaction of tissues to disease or injury and is marked by four signs: swelling, redness, heat, and pain.) When the plugged follicle can no longer hold its contents, it bursts and spills everything onto the nearby skin -- sebum, shed skin cells, and bacteria. Lesions or pimples develop as a result of the skin's being irritated.

People with acne frequently have a variety of lesions, some of which are shown in figures 2, 3, and 4. The basic acne lesion, called the comedo (kom'-e-do) or comedone, is simply an enlarged hair follicle plugged with oil and bacteria. This lesion is often referred to as a microcomedo because it cannot be seen by the naked eye. If the plugged follicle, or comedo, stays beneath the skin, it is called a closed comedo or whitehead. Whiteheads usually appear on the skin surface as small, whitish bumps. A comedo that reaches the surface of the skin and opens up is called a blackhead because it looks black on the skin's surface. This black discoloration is not due to dirt. Both whiteheads and blackheads may stay in the skin for a long time.

Other troublesome acne lesions can develop, including the following: 
Papules -- inflamed lesions that usually appear as small, pink bumps on the skin and can be tender to the touch 
Pustules (pimples) -- inflamed, pus-filled lesions that can be red at the base 
Nodules -- large, painful, solid lesions that are lodged deep within the skin 

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What Causes Acne?

The exact cause of acne is unknown, but doctors believe it results from several related factors. One important factor is rising hormone levels. These hormones, called androgens (male sex hormones), increase in both boys and girls during puberty and can cause the sebaceous glands to enlarge and make more sebum. Another factor is heredity or genetics. Researchers believe that the tendency to develop acne can be inherited from parents. For example, studies have shown that many school-age boys with acne have a family history of the disorder. 

What other Factors Can Contribute to Acne or Make It Worse?
 
Several factors can contribute to the cause of acne or make it worse. Changing hormone levels in girls and women may cause a flare in their acne 2 to 7 days before their menstrual period starts. Hormonal changes related to pregnancy or starting or stopping birth control pills can also cause acne. Stress, particularly severe or prolonged emotional tension, may aggravate the disorder.

In addition, certain drugs, including androgens, lithium, and barbiturates, are known to cause acne. Greasy cosmetics may alter the cells of the follicles and make them stick together. Friction caused by leaning on or rubbing the skin or the pressure from bike helmets, backpacks, or tight collars can contribute to or worsen acne. Also, environmental irritants (such as pollution and high humidity), squeezing or picking at blemishes, and hard scrubbing of the skin can make acne worse. 

What Myths exist about the Causes of Acne?
 
There are many myths about what causes acne. Chocolate and greasy foods are often blamed, but research has shown that foods seem to have little effect on the development and course of acne in most people. Another common myth is that dirty skin causes acne; however, blackheads and other acne lesions are not caused by dirt.

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Who Gets Acne?

People of all ages get acne, but it is most common in adolescents. Nearly 85 percent of adolescents and young adults between the ages of 12 and 24 develop the disorder. People of all races can have acne, but it is more common among Caucasians. For most people, acne tends to go away by the time they reach their thirties; however, some people in their forties and fifties continue to have the disorder. 

How Is Acne Treated?

By the time many people consult a doctor for their acne, they usually have tried a drawerful of over-the-counter (OTC) medications. Acne is often treated by a dermatologist, a doctor who specializes in diseases and disorders of the skin. Dermatologists treat all kinds of acne, particularly severe cases. Doctors who are general or family practitioners, pediatricians, or internists may treat patients with milder cases of acne.

The main goal of acne treatment is to prevent scarring. Additional goals are to reduce the number of painful lesions and to minimize the psychological stress and embarrassment caused by this disease. Doctors often use drug therapy as the first choice for treating acne. Drug therapy is aimed at reducing several problems that play a part in causing acne: abnormal clumping of cells in the follicles, increased oil production, the bacterium P. acnes, and inflammation. Depending on the severity of the person's acne, the doctor will recommend one of several OTC or prescription topical medications (medication applied to the skin) or a prescription systemic medication (medication taken by mouth). The doctor may suggest using more than one topical medication or using both an oral medication and a topical medication at the same time.

How do you Treat Blackheads, Whiteheads, and Mild Inflammatory Acne? 
Doctors usually recommend an OTC or prescription topical medication for people with blackheads, whiteheads, and mild inflammatory acne. Depending on the type of medication, a topical drug is applied directly to the acne lesions or to the entire area of skin affected. The medication helps limit the formation of new blackheads and whiteheads and decrease inflammation. 

What Treatments exist for Moderate to Severe Inflammatory Acne?
 
Patients with moderate to severe inflammatory acne may be treated with an OTC or prescription topical medication, a prescription oral medication, or a combination of these. 

Are there any Prescription Topical Medications?

Several types of prescription topical medications are used to treat acne, including benzoyl peroxide, antibiotics, tretinoin, adapalene, and azelaic acid. Prescription and OTC benzoyl peroxide work in the same way. Many doctors prescribe benzoyl peroxide instead of recommending OTC versions to make sure patients get the most desirable formulation (cream, gel, or lotion

What Are The Advantages of Isotretinoin?
 
Isotretinoin is a very effective medication that can help prevent extensive scarring in patients. After 16 to 20 weeks of treatment with isotretinoin, acne completely or almost completely goes away in most patients (up to 90 percent). For some people, however, the acne will come back, and they will need additional treatment with isotretinoin. 

What Are The Disadvantages of Isotretinoin?
 
Patients should carefully consider the several disadvantages of isotretinoin. The drug is not only expensive but is also linked to some adverse effects that can be severe. Possible side effects include inflammation of the lip and mucous membrane of the eye; dry mouth, nose, or skin; itching; nosebleeds; muscle aches; photosensitivity; and, rarely, decreased night vision. Other more serious side effects include increased blood cholesterol, lipid, and triglyceride levels and abnormal liver enzymes. To make sure isotretinoin is stopped if these side effects occur, the doctor usually monitors a patient's complete blood count, blood chemistries, cholesterol, triglycerides, and liver enzymes before therapy is started and periodically during treatment. All of these side effects usually go away after the medication is stopped. Patients who experience side effects while using isotretinoin should tell their doctor. The doctor may be able to reduce the dose of the drug so that the side effects are decreased or stopped.

The most serious potential adverse effect of isotretinoin is that it is teratogenic: it can cause birth defects in the developing fetus of pregnant women who take the drug. Therefore, it is crucial that women of childbearing age are not pregnant and do not get pregnant while taking isotretinoin. Women must use an appropriate birth control method for 1 month before therapy begins, during the entire course of therapy, and for 1 full month after therapy stops. Women should talk to their doctor about when it is safe to get pregnant after therapy with isotretinoin has stopped

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