Acne
Acne Vulgaris (commonly
called Acne) is a skin disease, caused by changes in the pilosebaceous units
(skin structures consisting of a hair follicle and its associated sebaceous
gland). Severe acne is inflammatory, but acne can also manifest in noninflammatory
forms.Acne lesions are commonly referred to as pimples, spots, or zits.Acne
is most common during adolescence, affecting more than 85% of teenagers, and
frequently continues into adulthood. For most people, acne diminishes over time
and tends to disappear, or at least decrease, after one reaches his or her early
twenties. There is, however, no way to predict how long it will take for it
to disappear entirely, and some individuals will continue to suffer from acne
decades later, into their thirties and forties and even beyond.
Causes
of Acne
Acne develops as a result of blockages in follicles. Hyperkeratinization and
formation of a plug of keratin and sebum (a microcomedo) is the earliest change.
Enlargement of sebaceous glands and an increase in sebum production occur with
increased androgen (DHEA-S) production at adrenarche. The microcomedo may enlarge
to form an open comedo (blackhead) or closed comedo (whitehead). In these conditions
the naturally occurring largely commensual bacteria Propionibacterium acnes
can cause inflammation, leading to inflammatory lesions (papules, infected pustules,
or nodules) in the dermis around the microcomedo or comedo, which results in
redness and and may result in scarring or hyperpigmentation.