The causes of acne are linked to the changes that take place as young people mature from childhood to adolescence (puberty). The hormones that cause physical maturation also cause the sebaceous(oil) glands of the skin to produce more sebum (oil). During puberty, the cells of the skin that line the follicle begin to shed more rapidly. In people who develop acne, cells shed and stick together more so than in people who do not develop acne. When cells mix with the increased amount of sebum being produced, they can plug the opening of the follicle. Meanwhile, the sebaceous glands continue to produce sebum, and the follicle swells up with sebum. In addition, a normal skin bacteria called P. acnes, begins to multiply rapidly in the clogged hair follicle. In the process, these bacteria produce irritating substances that can cause inflammation. Sometimes, the wall of the follicle bursts, spreading inflammation to the surrounding skin. This is the process by which acne lesions, from blackheads to pimples to nodules, are formed.

Many people still believe that acne is caused by dirty skin. The truth is, washing alone will not clear up or prevent acne. Washing does, however, help remove excess surface oils and dead skin cells. Many people use all kinds of products, including alcohol-based cleansers, and scrub vigorously, only to irritate the skin further and worsen their acne. Washing the skin twice a day gently with water and a mild soap is usually all that is required.

Stress is commonly blamed for the development of acne. Stress can have many physiologic effects on the body, including changes in hormones that may theoretically lead to acne. In some cases the stress may actually be caused by the acne lesions, not the other way around! If the acne is being treated effectively, stress is not likely to have much impact on the majority of people.

Usually, acne begins at puberty and is gone by the early 20s. In some cases, acne may persist into adulthood. Such types of acne include severe forms that affect the body as well as the face (which afflict males more than females) and acne associated with the menstrual cycle in women. In other cases, acne may not present itself until adulthood. Such acne is more likely to affect females than males. There are several reasons for this. As females get older, the pattern of changes in hormones may itself change, disposing sebaceous glands to develop acne. Ovarian cysts and pregnancy may also cause hormonal changes that lead to acne. Some women get acne when they discontinue birth control pills that have been keeping acne at bay. Sometimes young women may wear cosmetics that are comedogenic-that is, they can set up conditions that cause comedones to form.

Acne is not caused by food. Following a strict diet will not, clear your skin. While some people feel that their acne is aggravated by certain foods, particularly chocolate, colas, peanuts, shellfish and some fatty foods, there is no scientific evidence that suggests food causes or influences acne. Avoid any foods which seem to worsen your acne and, for your overall health, eat a balanced diet, but the diet shouldn't really matter if the acne is being appropriately treated.

Many patients feel that sunlight improves their acne lesions and go to great lengths to find sources of ultraviolet light. There is no proven effect of sunlight on acne. In addition, ultraviolet light in sunlight increases the risk of skin cancer and early aging of the skin. It is, therefore, not a recommended technique of acne management, especially since there are many other proven forms of treatment for acne. Moreover, many acne treatments increase the skin's sensitivity to ultraviolet light, making the risk of ultraviolet light exposure all the worse.

Everyone's acne must be treated individually. If you have not been able to control or reduce it immediately consult a dermatologist. Your dermatologist will decide which treatments are best for you.

Look for "noncomedogenic" cosmetics and toiletries. These products have been formulated so that they will not cause acne. Some acne medications cause irritation or pronounced dryness particularly during the early weeks of therapy, and some cosmetics and cleansers can actually worsen this effect. The choice of cosmetics and cleansers should be made by your dermatologist. Heavy foundation makeup should be avoided. Most acne patients should select powder blushes and eye shadow over cream products because they are less irritating and noncomedogenic. Camouflaging techniques can be used effectively by applying a green undercover cosmetic over red acne lesions to promote color blending.

Yes. In general, acne lesions should not be picked or squeezed by the patient. In particular, inflammatory acne lesions should never be squeezed. Squeezing forces infected material deeper into the skin, causing additional inflammation and possible scarring.

Scarring is best prevented by getting rid of the acne. Dermatologists can use various methods to improve the scarring caused by acne. The treatment must always be individualized for the specific patient. Chemical peels may be used in some patients, while dermabrasion or laser abrasion may benefit others. It is important that the acne be well controlled before any procedure is used to alleviate scarring.

The time for improvement depends upon the product being used, but in almost all cases it is more a matter of weeks or months instead of days. Most dermatologists would recommend the use of a medication or combination of medications daily for 4 to 8 weeks before they would change the treatment. It is very important for patients to be aware of this time frame so they do not become discouraged and discontinue their medications. Conversely, if you see no change whatsoever, you might want to check with your dermatologist regarding the need to change treatments.

Always use your medication exactly as your dermatologist instructed. Using topical medications more often than prescribed may actually induce more irritation of the skin, redness and follicular plugging, which can delay clearing time. If oral medications are taken more frequently than prescribed, they won't work any better, but there is a greater chance of side effects.

Topical acne medications are supposed to be used on all acne-prone areas, not just individual lesions. Part of the goal is to treat the skin before lesions can form and to prevent formation, not just to treat existing lesions. Patients are generally advised to treat all of the areas (forehead, cheeks, chin and nose) that tend to break out rather than just individual lesions.

If your dermatologist says you can stop, then stop--but follow your dermatologist's instructions. Many times patients will stop their medication suddenly only to have their acne flare up several weeks later. If you are using multiple products, it may be advisable to discontinue one medication at a time and judge results before discontinuing them all at once. Ask your dermatologist before you stop using any of your medications.

Check with your dermatologist. If you were taking one dose a day of an antibiotic, you could probably take it in the morning, at midday or in the evening, although you should pick one time of day and stay with it throughout your treatment. With oral medications prescribed twice a day or three times a day, you should try your best to spread out the doses evenly. Some antibiotics should be taken on an empty or nearly empty stomach. For optimal results with topical treatments, you should strictly follow your dermatologist's recommendations. For example, if instructed to apply benzoyl peroxide in the morning and a topical retinoid at bedtime, it is important to follow these directions strictly. If the two were applied together at bedtime, for example, you could decrease the efficacy of the treatment because of chemical reactions that make them less effective.

This is a common problem. Many patients try to associate taking their medication with a routine daily event such as brushing teeth or applying makeup. It also helps to keep the medication close to the area where the reminder activity is carried out. In most cases, if you miss a day of your oral treatment, do not double up the next day; rather, get back to your daily regimen as soon as possible--but there may be different instructions for different oral medications. Ask your dermatologist about what to do if you miss a dose of your particular medication.