Acne (acne vulgaris, common acne) is a disease of the hair follicles of the face, chest, and back that affects almost all males and females during puberty; the only exception being teenage members of a few primitive isolated tribes living in Neolithic societies. It is not caused by bacteria, although bacteria play a role in its development. It is not unusual for some women to develop acne in their mid- to late-20s.

Acne appears on the skin as...

• tender red bumps also known as pimples or zits,
• congested pores ("comedones"), also known as blackheads or whiteheads,
• pustules, and occasionally as
• cysts (deep pimples, boils).

You can do a lot to treat your acne using products available at a drugstore or cosmetic counter that do not require a prescription. However, for tougher cases of acne, you should consult a physician for treatment options.

What causes acne?

No one factor causes acne. Acne happens when sebaceous (oil) glands attached to the hair follicles are stimulated at the time of puberty by elevated levels of male hormones. Sebum (oil) is a natural substance which lubricates and protects the skin. Associated with increased oil production is a change in the manner in which the skin cells mature so that they are predisposed to clog the follicular openings or pores. The clogged hair follicle gradually enlarges, producing a bump. As the follicle enlarges, the wall may rupture, allowing irritating substances and normal skin bacteria access into the deeper layers of the skin, ultimately producing inflammation.

Inflammation near the skin's surface produces a pustule; deeper inflammation results in a papule (pimple); deeper still and it's a cyst. If the oil breaks though to the surface, the result is a "whitehead." If the oil accumulates melanin pigment or becomes oxidized, the oil changes from white to black, and the result is a "blackhead." Blackheads are therefore not dirt and do not reflect poor hygiene.

Here are some factors that don't usually play a role in acne:

• Heredity
• Food
• Dirt
• Stress

In occasional patients, the following may be contributing factors:

• Pressure
• Drugs
• Occupations
• Cosmetics

Acne treatments 

• reducing oil production
• speeding up skin cell turnover
• fighting bacterial infection
• reducing the inflammation 

With most prescription acne treatments, you may not see results for four to eight weeks, and your skin may get worse before it gets better.

Types of acne treatments include:

• Over-the - counter topical treatments. Acne lotions may dry up the oil, kill bacteria and promote sloughing of dead skin cells. Over-the-counter (OTC) lotions are generally mild and contain benzoyl peroxide, sulfur, resorcinol, salicylic acid or lactic acid as their active ingredient. These products can be helpful for very mild acne. OTC acne medications may cause initial side effects — such as skin irritation, dryness and flaking — that often improve after the first month of therapy.
• Topical treatments available by prescription - If your acne doesn't respond to OTC treatments, you may want to see a doctor or dermatologist to get a stronger prescription lotion. Tretinoin (Avita, Retin-A, Renova), adapalene (Differin) and tazarotene (Tazorac, Avage) are examples of topical prescription products derived from vitamin A. They work by promoting cell turnover and preventing plugging of the hair follicles. A number of topical antibiotics also are available. They work by killing excess skin bacteria. Often, a combination of such products is required to achieve optimal results. A number of benzoyl peroxide and antibiotic combination medications are available, including different dose combinations of benzoyl peroxide and clindamycin (Benzaclin, Duac, Acanya) and benzoyl peroxide and erythromycin (Benzamycin). Prescription topical treatments for acne may cause skin side effects, such as stinging, burning, redness or peeling. Your doctor may recommend steps to minimize these side effects, including using a gradually increased dose, washing off the medication after a short application or switching to another medication.
• Antibiotics - For moderate to severe acne, you may need a short course of prescription oral antibiotics to reduce bacteria and fight inflammation. Since oral antibiotics were first used to treat acne, antibiotic resistance has increased significantly in people with acne. For this reason, your doctor likely will recommend tapering off these medications as soon as your symptoms begin to improve, or as soon as it becomes clear the drugs aren't helping — usually, within three to four months. In most cases, you'll use topical medications and oral antibiotics together. Studies have found that using topical benzoyl peroxide along with oral antibiotics may reduce the risk of developing antibiotic resistance. Antibiotics may cause side effects such as an upset stomach, dizziness or skin discoloration. These drugs also increase your skin's sun sensitivity and may also reduce the effectiveness of oral contraceptives.
• Isotretinoin - For deep cysts, antibiotics may not be enough. Isotretinoin (Accutane) is a powerful medication available for scarring cystic acne or acne that doesn't respond to other treatments. This medicine is reserved for the most severe forms of acne. It's very effective, but people who take it need close monitoring by a dermatologist because of the possibility of severe side effects. Isotretinoin is associated with severe birth defects, so it can't be safely taken by pregnant women or women who may become pregnant during the course of treatment or within several weeks of concluding treatment. In fact, the drug carries such serious potential side effects that women of reproductive age must participate in a Food and Drug Administration-approved monitoring program to receive a prescription for the drug.

Isotretinoin commonly causes side effects such as dry eyes, mouth, lips, nose and skin, as well as itching, nosebleeds, muscle aches, sun sensitivity and poor night vision. The drug may also increase the levels of triglycerides and cholesterol in the blood and may increase liver enzyme levels.

      In addition, isotretinoin may be associated with an increased risk of depression and suicide. Although this causal relationship has not been proved, doctors remain on alert for these signs in people who are taking isotretinoin. If you feel unusually sad or unable to cope while taking this drug, tell your doctor immediately.

• Oral contraceptives - Oral contraceptives, including a combination of norgestimate and ethinyl estradiol (Ortho-Cyclen, Ortho Tri-Cyclen), can improve acne in women. However, oral contraceptives may cause other side effects — such as headaches, breast tenderness, nausea and depression — that you'll want to discuss with your doctor. The most serious potential complication is a slightly increased risk of heart disease, high blood pressure and blood clots.
• Laser and light based therapies - it reach the deeper layers of skin without harming the skin's surface. Laser treatment is thought to damage the oil (sebaceous) glands, causing them to produce less oil. Light therapy targets the bacteria that cause acne inflammation. These therapies can also improve skin texture and lessen the appearance of scars. More research is needed to understand the most effective use of light and laser therapies in acne treatment, and experts currently recommend these approaches as stand-alone therapy only in people who can't tolerate approved acne medications. These therapies may be uncomfortable and may cause temporary skin problems that mimic a severe sunburn.
• Cosmetic procedures - Chemical peels and microdermabrasion may be helpful in controlling acne. These cosmetic procedures — which have traditionally been used to lessen the appearance of fine lines, sun damage and minor facial scars — are most effective when used in combination with other acne treatments. They may cause temporary, severe redness, scaling and blistering, and long-term discoloration of the skin.

Acne scar treatment

• Soft tissue fillers - Collagen or fat can be injected under the skin and into scars to fill out or stretch the skin, making the scars less noticeable. Results from this acne scar treatment are temporary, so you need to repeat the injections periodically.
• Dermabrasion - Usually reserved for more severe scarring, dermabrasion involves removing the top layer of skin with a rapidly rotating wire brush. Surface scars may be completely removed, and deeper acne scars may appear less noticeable. Dermabrasion may cause pigmentation changes for people with darker skin.
• Microdermabrasion - This newer acne scar treatment involves a hand-held device that blows crystals onto skin. These crystals gently abrade or "polish" the skin's surface. Then, a vacuum tube removes the crystals and skin cells. Because just the surface cells are removed, the skin isn't damaged. However, results are subtle and scars may still be noticeable, even after several sessions.
• Laser, light source and radiofrequency treatments - In laser resurfacing, a laser beam destroys the outer layer of skin (epidermis) and heats the underlying skin (dermis). As the wound heals, new skin forms. Less intense lasers (nonablative lasers), pulsed light sources and radiofrequency devices don't injure the epidermis. These treatments heat the dermis and cause new skin formation. After several treatments, acne scars may appear less noticeable. This means shorter recovery times, but treatment typically needs to be repeated more often and results are subtle.
• Skin surgery - A minor procedure (punch excision) cuts out individual acne scars. Stitches or a skin graft repairs the hole left at the scar site.

You can avoid or control most acne with good basic skin care and the following self-care techniques:

• Wash problem areas with a gentle cleanser. 
• Try over-the-counter acne lotion to dry excess oil and promote peeling. Look for products containing benzoyl peroxide or salicylic acid as the active ingredient.
• Avoid irritants.  Use products labeled "water-based" or "noncomedogenic." 
• Watch what touches your face. Keep your hair clean and off your face. 
• Don't pick or squeeze blemishes.