A
acne INFLAMMATIONof the SKIN’s sebaceous struc-
tures, also called acne vulgaris, that results in
eruptions on the skin surface commonly called
pimples, whiteheads, and blackheads. Acne occurs
when excessive sebum traps BACTERIA and skin
cells, clogging the follicles. The clogged follicles
provide an ideal incubator for the bacteria Propi-
onibacterium acne,which is normally present on the
surface of the skin where continuous exposure to
the air keeps it in check. Within the airless envi-
ronment of a clogged hair follicle, however, these
anaerobic bacteria, which do not require oxygen,
thrive.
Acne is most common in PUBERTYand is a conse-
quence, most doctors believe, of the natural surge
in sex HORMONEproduction, notably TESTOSTERONE,
that heralds the onset of puberty. Testosterone
stimulates the sebaceous glands surrounding the
HAIRfollicles, increasing their production of sebum,
a thick, oily substance that helps lubricate the skin.
Women experience hormonal changes during MEN-
STRUATION, 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 sug-
ars, 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 seba-
ceous structures can contribute to or aggravate
acne outbreaks.
Acne commonly erupts on the face, upper
back, and chest as these areas contain large num-
bers of hair follicles. Acne seldom affects scalp fol-
licles. 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 straightfor-
ward. Doctors diagnose acne on the basis of its
appearance and the hormonal stages the individ-
ual 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 asPOLYCYSTIC OVARY SYN-
DROME(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. Prod-
ucts may be topical (applied to the affected areas
of the skin for localized effect) or systemic (med-
ications taken by mouth for generalized effect). P.
acnetends 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 leave131