The dark spots that can persist in the location where an acne pimple
used to be are caused by "post-inflammatory hyperpigmentation," a
common condition in which the skin darkens because of an
overproduction of melanin (a pigment that occurs naturally in the
body) in reaction to inflammation. The problem is seen more frequently
in people who have darker skin, but it can occur even in very
fair-skinned individuals. I've gathered some information that I hope
you will find helpful.
"Dark skin prone to developing 'dark spots.'
These darkened spots on the skin, which dermatologists call
'post-inflammatory hyperpigmentation,' can occur at the site of a
healed or healing inflamed acne lesion. Caused by excessive melanin
production, this darkening of the skin is a normal reaction when dark
skin becomes inflamed, such as after a rash, scratch or pimple. While
these spots tend to gradually disappear over time, they are the number
one complaint among dark-skinned patients with acne vulgaris...
When these spots appear, they can be treated with a topical
skin-lightening product. Some skin-lightening agents are available
over-the-counter, and stronger forms can be obtained from a
dermatologist. Dermatologists can also recommend cosmetic tips that
will make the spots less apparent. Additionally, some topical acne
treatments used by dermatologists may help fade the discoloration.
Sunscreen may help. Although there are no clinical studies to confirm
this, some dermatologists find that repeated sun exposure leads to
longer treatment time and that daily use of sunscreen (SPF of 15 or
higher) helps resolve the spots more quickly. Only sunscreen labeled
'noncomedogenic' should be used. 'Noncomedogenic' means the product
will not clog pores."
Skin Care Physicians
"Hyperpigmentation is a common, usually harmless condition in which
patches of skin become darker in color than the normal surrounding
skin. This darkening occurs when an excess of melanin, the brown
pigment that produces normal skin color, forms deposits in the skin.
Hyperpigmentation can affect the skin color of people of any race...
Most prescription creams used to lighten the skin contain
hydroquinone. Bleaches lighten and fade darkened skin patches by
slowing the production of melanin so those dark spots gradually fade
to match normal skin coloration. Prescription bleaches contain twice
the amount of hydroquinone, the active ingredient, as over-the-counter
skin bleaches. In more severe cases prescription creams with tretinoin
and a cortisone cream may be used. These may be somewhat irritating to
sensitive skin and will take 3-6 months to produce improvement.
There are now several highly effective laser treatments. The
q-switched ruby and other pigmented lesion lasers often remove pigment
Dermatologic Disease Database
"What is post-inflammatory hyperpigmentation?
It is a discolouration that is left on the skin after an underlying
skin disease has healed. The underlying skin disease may be trauma,
skin infection, eczema or a drug reaction. In dark-skinned persons,
the colour tends to be more intense and persists for a longer period.
The pigmentation tends to clear with time.
How is post-inflammatory hyperpigmentation treated ?
Usually, normal skin colour will return slowly over a period of
months. One should avoid further trauma to the area, e.g. frequent
rubbing and sunlight exposure. In hyperpigmentation, bleaching agents
such as those containing hydroquinone may be used. Occasionally a mild
steroid may help."
National Skin Center
"Color changes in acne in more common than scarring and can resolve
but may take years to completely disappear. Color changes come in
three basic flavors: post inflammatory erythema (pink and purple
patches at the site of acne lesions), post inflammatory
hyperpigmentation (brown/black discoloration at the site of the acne
lesion), and post inflammatory hypopigmentation (white marks at the
site of a healed acne lesion). Post inflammatory hyperpigmentation is
very common in those with darker skin tones or in those who tan easily
and can significantly worsen the appearance of acne."
"Inflammation caused by acne leads to redness of the skin. Redness
usually starts when the acne lesion is active. Even after the acne
lesion has improved, however, inflammation may continue deep in the
skin, causing persistent redness of the skin. Inflammation also
stimulates the production of the pigment molecule called melanin,
leading to brown or black discoloration. Thus, in those who tan easily
or with darker skin tones, melanin production is stimulated by the
inflammation leading to brown discoloration around the acne lesion.
Although the discoloration lasts longer than the acne lesion itself,
the discoloration will fade with time- sometimes several months."
"What treatment options are available for acne discoloration?
Creams (topical therapies)
Over-the-counter bleaching creams may improve hyperpigmentation from
acne. Over-the-counter creams contain 2 percent hydroquinone, a
bleaching agent. Prescription creams may use single agents, such as
Retin-A (tretinoin) or combinations of medications such as
hydroquinone with tretinoin plus a cortisone cream. These treatments
can be quite effective when used properly. You need to discuss the
risks of each medication with your doctor.
What are the risks?
In general topical treatments have fewer side effects. In general, the
most common side effect is irritation and redness. However, another
less common side effect is discoloration. You and your physician will
decide on the right treatment for you.
What new treatments are available for the treatment of discoloration from acne?
In general, chemical are effective for improving discoloration from
acne. More superficial peels have proven effective which is beneficial
because there is less risk and less recovery time. However, several
peels may be needed to obtain the desired effect.
Microdermabrasion is a popular procedure which is classified as light,
or very superficial dermabrasion. This method employs aluminum oxide
crystals that are propelled at the skin and immediately sucked up.
Although not scientifically proven to improve the appearance of skin,
many patients report that their skin feels smoother. It is used to
treat acne, and the hyperpigmentation caused by acne. It is also
popular because it is painless and there is no recovery time after the
procedure. However, to effectively treat acne discoloration, up to 15
treatments may be necessary which can be very expensive. Newer devices
now are crystal-less."
"One of the major concerns of patients of color who experience acne
are the dark spots or discolorations that occur. These blemishes are
the result of increased pigment (melanin) deposition caused by the
inflammation of the skin form the acne. So therefore, squeezing acne
lesions is not the only cause in the development of blemishes...
Over the counter products that contain salicylic acid, glycolic acid
or benzoyl peroxide are excellent anti-acne agents as well as
exfoliants. While eliminating acne, they can also produce an even tone
Use products containing hydroquinone (HQ) 1-2% to remove dark spots
My Google search strategy:
Google Web Search: acne "dark spot OR spots"
Google Web Search: "post-inflammatory hyperpigmentation" acne
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medical advice; the material I've assembled for you is intended as
general information, and should not be viewed as any kind of
diagnosis, nor as a substitute for the services of a medical
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