What is Hyperpigmentation?
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.
Normal skin contains cells called melanocytes. These cells produce melanin, the substance that gives skin its color.
Skin with too much melanin is called hyperpigmented skin.
Skin with too little melanin is called hypopigmented skin.
Pale skin areas are due to too little melanin or underactive melanocytes. Darker areas of skin (or an area that tans more easily) occurs when you have more melanin or overactive melanocytes.
Causes & types of hyperpigmentation:
Darkened patches are usually found on the hands and face or other areas frequently exposed to the sun.
-Melasma or chloasma spots:
similar in appearance to age spots but are larger areas of darkened skin that appear most often as a result of hormonal changes. Pregnancy, for example, can trigger overproduction of melanin that causes the "mask of pregnancy" on the face and darkened skin on the abdomen and other areas. Women who take birth control pills may also develop hyperpigmentation because their bodies undergo similar kind of hormonal changes that occur during pregnancy. If one is really bothered by the pigment, the birth control pills should be stopped.
- Small brown spots that can appear anywhere on the body, but are most common on the face an arms. Freckles are an inherited characteristic.
- Changes in skin color can result from outside causes. For example, skin diseases such as acne may leave dark spots after the condition clears. Other causes of dark spots are injuries to the skin, including some surgeries.
- Sun exposure:
can make freckles, age spots, and other darkened skin patches darker or more pronounced. This happens because melanin absorbs the energy of the sun's harmful ultraviolet rays in order to protect the skin from overexposure. The usual result of this process is skin tanning, which tends to darken areas that are already hyperpigmented. Wearing a sunscreen is a must. The sunscreen must be "broad spectrum" (i.e. it blocks both UVA and UVB). A single day of excess sun can undo months of treatment.
Protect your skin from the sun by taking the following precautions:
Wear protective clothing such as hats, long-sleeved shirts, long skirts, or pants.
Use sunglasses to protect your eyes.
Try to avoid sun exposure at midday, when sunlight is most intense.
Use high quality broad spectrum sunscreens, preferably with SPF (sun protection factor) ratings of at least 30.
Apply sunscreen at least a half hour before exposure, and reapply frequently. Use sunscreen in the winter, too.
Treatment of hyperpigmentation problems / skin lightening:
The goal is to reduce the hyperpigmentation without causing undesirable hypopigmentation or irritation in the surrounding normally pigmented skin. The psychosocial impact caused by these disorders must be considered. Although there are many effective therapeutic modalities available, there are potentially significant side-effects associated with treatment. Hyperpigmentation treatments include topical lightening agents, laser / intense pulsed light, cryotherapy and chemical peels. None of the methods is optimal for every individual or for every hyperpigmentation problem.
Generally hyperpigmentation treatment must follow one or a combination of the following strategies:
Controlling of melanin formation
by inhibiting the enzyme tyrosinase, which is responsible for the conversion of DOPA to melanin in melanocytes, resulting in the reduction of melanin synthesis. Many topical agents are used for this purpose such as:
which is the most famous skin lightening agent for decades due its high effectiveness. But, unfortunately, some recent studies indicated the risk of developing skin cancer upon using it especially in higher concentrations . beside its known adverse reactions including irritation & hypopigmentation of the surrounding normal skin.
which is a hydroquinone derivative with a fewer side effects.
which appears to be comparable to hydroquinone in effectiveness, but found to be relatively unstable in skin care formulations. Beside unclear possible risk of cancer.
which is most commonly used for acne. It also suppresses the proliferation of melanocytes, apparently by reducing the rate of DNA synthesis. Topical azelaic acid has no or little depigmentation effect on normally pigmented skin. Apparently, azelaic acid is much more active against abnormal melanin synthesis and abnormal melanocytes.
Peeling & exfoliating action
to increase the turnover of epidermal cells causing more melanin to wash out of the skin. Many topical agents, also, are used like:
Alpha hydroxyl acids ( AHA )
Chemical peels and laser resurfacing
Skin resurfacing, whether with a laser or a chemical agent, may significantly reduce pigmented lesions. However, these treatments are rarely used to treat hyperpigmentation alone due to cost, inconvenience and side effects, including hypopigmentation and hyperpigmentation.
Nonablative laser and intense pulsed light
Melanin absorbs light predominantly in the green-yellow range. Hence high intensity directed light in that range may heat up and eliminate hyperpigmented lesions without too much damage to the surrounding skin. This approach is more for localized lesions such as age spots. The devices used to treat hyperpigmentation include Intense Pulsed Light (IPL) systems, pulsed dye lasers and others. These treatments are expensive and, while the effect on localized lesions may be quick and dramatic, the outcome is somewhat unpredictable (hypopigmentation or hyperpigmentation may develop).
Cryotherapy is useful only for small, well-localized hyperpigmented lesions, such as age spots. For such problems, cryotherapy (freezing off the lesion) is as effective as laser treatments but more reliable, less expensive and less likely to cause side effects.