Acne vulgaris is the most common skin disorder in adolescents.
It is a multifactorial disease characterized by chronic inflammation
of the pilosebaceous units of certain areas (face and trunk) that manifests
as comedones, papules, nodules, cysts, or papulopustules, often
but not always followed by scars.
Neonatal acne (presenting between the age of 2 weeks and 3 months
of life) is common and self-limited. Infantile acne (presenting
between 3 and 6 months of age) may foreshadow more severe acne later
Age Typically begins at puberty.
Gender M > F, and males tend to
be more severely affected.
Prevalence Approximately 85% of
12- to 24-year-old patients have some form of acne. Forty to fifty
million people in the United States have acne annually.
Drugs Systemic corticosteroids,
iodides, bromides, anticonvulsants (phenytoin and trimethadione),
and antidepressants (lithium) can exacerbate acne in susceptible
Genetic Aspects Family history
may be a predictor of acne severity.
Other Factors Emotional stress,
lack of sleep, and menses can cause exacerbations. Pressure or rubbing
of skin can cause local outbreaks (acne mechanica). Androgen excess
can also lead to severe refractory cases.
The lesions of acne (comedones) are the result of genetics (increased
number and size of sebaceous glands), hormones (androgens), bacteria
(Propionibacterium acnes), and the inflammatory response in the
pilosebaceous unit. Androgens stimulate sebaceous glands to produce
larger amounts of sebum; bacteria contain lipase that converts lipids
into fatty acids. Both excess sebum and fatty acids cause the corneocytes
to block the pilosebaceous unit and comedones are formed. If the
comedo is open to the skin surface, the oxidized keratin protrudes
and darkens in color (blackheads). Closed comedones may break under
the skin and the contents (sebum, lipid, fatty acids, keratin) enter
the dermis, provoking inflammation (papules, pustules, nodules).
Rupture plus intense inflammation may lead to scarring.
Duration of Lesions Weeks to months.
Season Worse in fall and winter.
Symptoms Itching or pain in lesions
(especially nodulocystic type).
- Comedones: open comedones are “blackheads,” closed
comedones are “whiteheads” (Fig. 6-1A).
- Papules with or without inflammation, pustules (Fig. 6-1B).
- Nodules, noduloulcerative lesions, 2 to 5 cm in diameter.
- Postinflammatory hyperpigmentation.
- Scars. Atrophic depressed (often pitted) or hypertrophic (keloid)
Shape Round; nodules may coalesce
to form linear plaques.
Acne vulgaris A. Scattered
inflammatory papules and pustules on the ...