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How does Acne Develop?
Acne is a skin disorder which is caused by plugged pores on the skin.
Acne lesions arise through pilosebaceous units, which are made of sebaceous
glands and hair follicles in the middle layer of skin called the dermis.
Pilosebaceous units are found all over the body except in the palms
of hands and the bottoms of feet. That’s why we do not have body
hair or oil glands in these places, and thus no acne.
Pilosebaceous units are the densest on the face, upper neck and the
chest. The primary cause of acne is obstruction of pilosebaceous canal,
which can take place due to various reasons.
The first and foremost reason for acne development is the overproduction
of sebum, which clogs the pilosebaceous canal. Sebum production is affected
by male hormones called androgens. That’s why any fluctuation
in hormonal balance or stimulation of male hormones due to various reasons
always leads to acne.
With excess sebum production, the cell lining of the follicle wall
also starts to overproduce (Ductal hypercornification).These dead cells
along with the extra amount of sebum plugs the canal and accumulates
there. Soon, the bacteria present on the skin surface, namely Propionibacterium
acnes, invade these clogged ducts and attract white blood cells of the
immune system. The infected area becomes inflamed due to the reaction
between white blood cells and the bacteria.
The development of acne takes place over 2-3 weeks before it appears
on the surface of the skin. It starts as a blemish in the sebaceous
hair follicle. Deep within the hair follicle, two processes continually
take place. The produced sebum mixes with old, dying cells and gets
excreted through the hair follicle pores. Old cells die so that new
cells can be generated and skin can rejuvenate itself.
In normal circumstances, the dead cells that are shed gradually keep
pace with the formation of new cells. This shedding of skin cells is
different in different people. In some people, the skin sheds dead cells
evenly. In other cases the shedding of the skin becomes uneven and the
dead cells accumulate in the follicles, thus effectively plugging the
pore with sebum and bacteria.
Acne can be non-inflammatory or inflammatory. Non-inflammatory acne
is the common form of acne called comedo. When a comedo’s pore
is closed and the plug remains inside the skin, it is called a whitehead.
These appear on the skin as small, whitish bumps.
When the pore is open and the plug pushes through the skin on the outer
surface, it is called a blackhead. The opening of this blackhead appears
dark in color not because of the accumulation of dirt, but due to the
build up of pigment melanin.
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Although these forms of acne are non-inflammatory, if these are not
controlled, they may turn into inflammatory acne lesions which are red,
swollen, and take time to heal. These are papules, pustules, nodules,
cysts, maculae and scars.
Papules are red pimples or lesion. Pustules are just like papules but
its center is filled with pus. Nodules are deep-seated acne which may
take up to 8 weeks to heal. Cysts are not a common type of acne but
this is the most serious example of acne, which can reach up to several
centimeters of diameter. Cystic acne is considered to be a severe form
and needs immediate medical attention.
Acne can develop in different age groups of people. Infants to people
in their 40s can suffer from acne, as it is largely linked with the
hormonal imbalance. Infant acne develops because of the hormonal changes
occurring in mother which pass through the placenta and affect the infant.
This acne can appear before birth or between 3 to 6 months. Baby boys
are more likely to develop this acne than baby girls. Usually the infantile
acne does not leave scars and gets healed naturally, but it also may
develop in that person’s teen years as acne vulgaris.
There are some unusual forms of acne which develop due to different
reasons other than those causing the normal acne (acne vulgaris). Acne
Keloiddalis is one such form which is commonly found in people with
strong, curly hair. Interestingly, this kind of acne is caused by the
hair itself which curls and penetrates the follicular wall. This leads
to blockage of the follicle and obstruction of normal sebum secretion.
Because of this a fibrous tissue develops in the follicle with inflammation.
This area often becomes infected and shows typical acne symptoms.
Other Resources:
Medical Center of Central
Georgia
Hippocrates World
Site
http://www.acne.com
www.acne.com
http://www.acne-treatment.ca/acne-treatment.html
Yale New Haven children’s Hospital
http://www.dotpharmacy.com/upacne.html
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