Table of Contents
Definition of Acne
Acne occurs when excessive sebum traps BACTERIA and skin cells, clogging the follicles. The clogged follicles provide an ideal incubator for the bacteria Propionibacterium acne, which is normally present on the surface of the skin where continuous exposure to the air keeps it in check. Within the airless environment of a clogged hair follicle, however, these anaerobic bacteria, which do not require oxygen, thrive.
Acne is most common in PUBERTY and is a consequence, most doctors believe, of the natural surge in sex HORMONE production, notably TESTOSTERONE, that heralds the onset of puberty. Testosterone stimulates the sebaceous glands surrounding the HAIR follicles, increasing their production of sebum, a thick, oily substance that helps lubricate the skin.
Women experience hormonal changes during MENSTRUATION, pregnancy, and MENOPAUSE that may cause acne outbreaks, because estrogen suppresses sebum production. Newborn infants may develop acne during the first few weeks of life, a reaction to the surge of hormones the infant receives from his or her mother in the few days before birth. Contrary to popular belief, foods high in fats or sugars, such as french fries or donuts, have little if any influence on acne. However, cosmetics and oily products applied to the skin that block the sebaceous structures can contribute to or aggravate acne outbreaks.
Acne commonly erupts on the face, upper back, and chest as these areas contain large numbers of hair follicles. Acne seldom affects scalp follicles. An outbreak begins as small, reddened bumps, called comedones or papules, that may hurt or itch. As the sebaceous structures become more inflamed, the bumps enlarge into closed (whiteheads) or open (blackheads) lesions. Lesions that form near the surface of the follicles are pimples; those that expand below the surface of the skin are nodules or cysts.
The most serious form of acne is nodulocystic acne, in which numerous nodules and cysts form deep within the follicles though inflammation that extends above the skin’s surface. Nodulocystic acne typically leaves scars or pits after the lesions heal, and may extensively damage the skin.
Symptoms and Diagnostic Path
The symptoms of acne are its characteristic bumps and lesions, making diagnosis fairly straightforward. Doctors diagnose acne on the basis of its appearance and the hormonal stages the individual may be going through. Acne that does not fit the characteristic presentation may be a symptom of an endocrine disorder that allows elevated testosterone levels, such as POLYCYSTIC OVARY SYNDROME (PCOS) or CUSHING’S SYNDROME. Laboratory tests to measure hormone levels can assess this possibility. Rarely, the doctor may choose to BIOPSY several lesions to confirm the diagnosis.
Treatment Options and Outlook
Treatment for acne targets reducing inflammation, sebum production and accumulation, and the presence of infective agents such as P. acne. Products may be topical (applied to the affected areas of the skin for localized effect) or systemic (medications taken by mouth for generalized effect). P. acne tends to develop resistance to antimicrobial products over time, making it necessary to switch among medications for optimal effectiveness. Acne is self-limiting and will improve over time without treatment, though severe acne may leave scars. Products to treat mild to moderate acne are available without a doctor’s prescription. Prescription only medications, such as topical and oral antibiotics, are necessary for moderate to severe acne. Most people use several kinds of products concurrently.
Over-the-counter products and self-care
Products available without a doctor’s prescription to treat acne generally contain astringents, exfoliants, and antimicrobials, sometimes in combination with one another. The common product Clearasil, for example, combines resorcinol, which slows the production of keratocytes, and sulfur, an antimicrobial. Such products cleanse excess oils, debris, and dead cells from the skin. Antiseptic or antimicrobial substances help suppress P. acne and other bacteria normally present on the skin, reducing the potential for INFECTION and inflammation.
|COMMON INGREDIENTS IN OVERTHE-COUNTER ACNE PRODUCTS|
|benzoyl peroxide||antimicrobial, exfoliant|
|lactic acid||exfoliant, mild antimicrobial|
|salicylic acid||exfoliant, astringent|
The two general categories of medications doctors prescribe for acne are antibiotics and retinoids, in topical and oral forms. ANTIBIOTIC MEDICATIONS target bacteria such as P. acne. Oral antibiotic therapy may extend over six months or longer, at doses lower than those typically prescribed to treat acute infections.
Isotretinoin causes birth defects. Current practice standards require two negative pregnancy tests and use of reliable contraception (such as oral contraceptives) before dermatologists may prescribe isotretinoin therapy for women of childbearing age.
In people who have severe or pitting acne, treatment with oral isotretinoin nearly always ends further acne outbreaks because the isotretinoin permanently alters the structure and function of the sebaceous structures. However, oral isotretinoin has numerous, and potentially serious, side effects that make it a treatment option when other methods have failed to control the acne. All of the retinoids can cause BIRTH DEFECTS; women who are or could become pregnant should not use these medications. Oral contraceptives (birth control pills) often improve acne that follows the MENSTRUAL CYCLE.
|Commonly Prescribed Medications for Acne|
|erythromycin (topical and oral)||minocycline (oral)|
|tetracycline (topical and oral)||doxycycline (oral)|
|isotretinoin (topical and oral)||tretinoin (topical)|
|adapalene (topical)||tazarotene (topical)|
Acne is self-limiting. Most acne ceases when the body’s hormone levels stabilize. For adolescents, this occurs at the culmination of puberty, generally by the late teens (females) or early twenties (males). In women, acne outbreaks may occur regularly with the menstrual cycle. Acne related to the hormonal changes of pregnancy generally goes away within three months of childbirth. Acne is uncommon in postmenopausal women.
Risk Factors and Preventive Measures
Because acne results from a convergence of factors, key among them hormonal shifts in the body, there are no known measures for preventing its occurrence. Many myths have prevailed through the years about the relationship between foods and acne. Though nutritious eating habits are important for overall health and development as well as the skin’s general health, foods do not influence the course or severity of acne. Similarly, though poor hygiene contributes to numerous problems with the skin and may exacerbate acne by encouraging the growth of bacteria, it does not in itself cause acne.
Diligent daily hygiene, such as gentle cleansing with an antibacterial soap, helps prevent acne lesions from becoming infected. Zealous washing and scrubbing can aggravate acne, causing increased inflammation and irritation. Harsh soaps that dry the skin may temporarily reduce surface oils but can cause flaking and other problems. Using an astringent according to the doctor’s instructions can draw excess oils from the sebaceous structures without so much irritation to the surrounding skin. Dermatologists often recommend lubricating lotions and creams that do not block the pores to help maintain the skin’s moisture.