Acne
vulgaris starts with the formation of a microcomedo as shown
in figure 1. Stage two consists of non-inflammatory lesions,
closed comedones (whiteheads) and open comedones (blackheads).
The non-inflammatory lesions can turn into inflammatory lesions.
Dependent on the degree of severity, the inflammatory lesion
range comprises of papules, pustules and nodulocystic lesions.
The stimulus for microcomedo formation is still uncertain.
The strongest leads implicate androgen hormones, alterations
in follicular linoleic acid levels, and the inflammatory cytokine
interleukin-1a. Other factors, such as genetic predisposition,
stress, and diet, may also affect the development and severity
of acne.
Present therapeutic
approaches to acne
Topical and systemic therapies are the major therapeutic strategies
for the treatment of acne today.
Dependent upon the severity of the lesions
a single or combined therapy is applied. In general, the topical
and systemic therapies aim at inhibition of hyperkeratosis,
follicular plugging, diminishment of sebum production, reduction
of bacterial load (e.g. Propionibacterium acnes) and inflammatory
responses. The main active compounds of therapies (in gel,
cream and solution formulations) consist of retinoids and
antibiotics. Hormonal treatment is occasionally used for most
types of acne in both adult and adolescent females. These
therapies are often accompanied by adverse side effects.
Of the current acne treatments most have
minimal information on the mechanism of action. The mechanism
of action in the treatment of acne with Benzoly peroxide is
unclear, although the antibiotic activity is believed to be
predominate. The exact mechanism of action of oral retinoids
in acne treatments is also not known. |
"Acne
vulgaris starts
with
the formation of a microcomedo..."
|
Acne
vulgaris
clinical terminology |
Acne vulgaris
a chronic inflammatory ailment of the pilosebaceous unit.
The existence of a comedo is critical for the diagnosis.
Microcomedo
First stage in acne vulgaris: follicular plugging of the
duct of a pilosebaceous unit (which consists of a hair follicle
and a sebaceous gland).
Comedones
A comedone is a sebaceous follicle plugged with sebum, dead
cells from inside the sebaceous follicle, tiny hairs, and
sometimes bacteria (e.g. Propionibacterium acnes). When
a comedone is open, it is often named a blackhead since
the exterior of the plug in the follicle has a dark appearance.
A closed comedone is generally described as a whitehead
since its appearance is usually that of a skin-colored bump
in the skin.
Papule
An inflammatory comedone that resembles a small, red bump
on the skin.
Pustule
An inflammatory comedone that resembles a whitehead with
a ring of redness around it.
Nodulocystic
lesions A severe form of acne that is characterized
by copious deep, inflamed bumps (nodules) and large, pus-filled
lesions that resemble sores (cysts). The severe inflammation
can cause the acne to become exceedingly red or purple.
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