Acne

Definition

Acne is a common inflammatory skin disease characterized by pimples on the face, chest, and back. It occurs when the pores of the skin become clogged with oil, dead skin cells, and/or bacteria.

Description

Acne vulgaris, the medical term for common acne, is the most common skin disease. It affects nearly 17 million people in the United States. While acne can arise at any age, it usually begins at puberty and worsens during adolescence. Nearly 85% of people develop acne some time between the ages of 12 and 25 years old. Up to 20% of women develop mild acne. It is also found in some newborns.

The sebaceous glands lie just beneath the skin's surface. They produce sebum, an oily secretion that helps to preserve the flexibility of the hair and moisturizes the skin. These glands and the hair follicles within which they are found are called sebaceous follicles. These follicles open onto the skin through pores that allow the sebum to reach the hair shaft and the skin. In certain situations, the glands excrete excess sebum and it cannot be cleared from the pores efficiently. This happens, for instance, at puberty when increased levels of the androgen hormones cause overproduction of sebum. In addition, cells lining the follicle are shed too quickly and begin to clump together. The excess sebum combines with the dead cells, and forms a plug, or comedo (also called comedones), that blocks the pore, which is not usually seen. When the follicle begins to bulge and show up as a small whitish bump mostly under the skin, it is called a whitehead. If the comedo opens up, the top surface of the plug darkens, and it is referred to as a blackhead.

Infection results when a plugged follicle is invaded by Propionibacterium acnes, a bacteria that normally lives on the skin, and possibly other microorganisms. The bacteria produce chemicals and enzymes that bring on inflammation. Pimples are the result of infected blackheads or whiteheads that rupture, releasing sebum, bacteria, dead skin, and white blood cells onto the surrounding tissues. Inflamed pimples near the skin's surface are called papules; they are red and raised, and may be quite tender to the touch. The papules may become filled with pus, and are then called pustules. If the follicle continues to enlarge rather than rupture, it forms a closed sac, called a cyst, which can be felt as a lump under the skin. Large hard swellings deep within the skin are called nodules. Both nodules and cysts may cause pain and scarring.

Causes and Symptoms

The exact cause of acne is mostly unknown. Sometimes when acne in women is due to excess male hormone production, it is diagnosed by the fact to an onset of the condition in adulthood; excessive growth of hair, especially in places not usual on a female, called hirsuitism; irregular menstrual cycles; and premenstrual flare-ups of acne.

Many alternative practitioners assert that acne is often related to a condition of toxicity in the intestines or liver. This may be due to the presence of bacteria such as Clostridia spp. and Yersinia enterocolitica, a low-fiber diet; a lack of friendly gut flora such as Lactobacillus spp.; an intestinal overgrowth of Candida albicans; and food allergies.

The interaction between the body's hormones, skin protein, skin secretions, and bacteria determines the course of acne. Several other factors have also been shown to affect the condition:

• Age. Teenagers are more likely than anyone to develop acne.
• Gender. Boys have more severe acne and develop it more often than girls.
• Disease. Hormonal disorders can complicate acne in girls.
• Heredity. Individuals with a family history of acne have greater susceptibility to the condition.
• Hormonal changes. Acne can flare up before menstruation, during pregnancy, and menopause.
• Diet. Although they are not the primary cause of acne, certain foods may bring on flare-ups or make the condition worse.
• Drugs. Acne can be a side effect of antibiotics, oral contraceptives, and anabolic steroids.
• Personal hygiene. Use of abrasive soaps, hard scrubbing of the face, or handling pimples will often make them worse.
• Cosmetics. Oil-based makeup and hair sprays worsen acne.
• Environment. Exposure to oils and greases, polluted air, and sweating in hot weather can all aggravate acne.
• Stress. Emotional stress may contribute to acne.
• Friction. Continual pressure or rubbing on the skin by such things as bicycle helmets, backpacks, or tight clothing, as well as hard scrubbing of the skin, can worsen acne.

The most common sites of acne are the face, chest, shoulders, and back, since these are the parts of the body where the most sebaceous follicles are found. In teenagers, acne is often found on the forehead, nose, and chin. As people get older, it tends to appear towards the outer part of the face. Adult women may have acne on their chins and around their mouths. The elderly often develop whiteheads and blackheads on the upper cheeks and skin around the eyes. Inflamed lesions may cause redness, pain, tenderness, itching, or swelling in affected areas.

Diagnosis

Acne has a characteristic appearance and is, therefore, not difficult to diagnose. A complete medical history should be taken, including questions about skin care, diet, factors that improve or worsen the condition, medication use, and prior treatment. Physical examination includes the face, upper neck, chest, shoulders, back, and other affected areas. Under good lighting, the doctor can determine what types and how many blemishes are present, whether they are inflamed, whether they are deep or superficial, and whether there is scarring or skin discoloration. Blood tests are done when the patient appears to have hormonal or other medical problems. Stool tests can be helpful in determining whether there is a bacterial or yeast overgrowth contributing to the condition. Food allergy testing should also be considered.