THE ORIGIN OF SKIN COLOR
The color that is seen in the stratum corneum is produced within the epidermis in a cell called the melanocyte. The melanocyte’s sole function is to produce melanin. Everyone has approximately the same number of melanocyte cells, but genetics cause the melanocytes of various individuals to produce different amounts of melanin.
The more melanin produced, the darker the skin will be. However, it is not only melanin that gives skin its color. Carotene produces a yellow to orange pigment that influences the color of the skin as well; carotene can give the skin a yellowish hue.
Thomas Fitzpatrick, a Harvard dermatologist, developed the Fitzpatrick Numerical Classification, which categorizes skin color as type I through type VI. It is a tool to determine how easily skin will burn when exposed to ultraviolet radiation. Many people with a heritage from the Mediterranean, Caribbean, Africa, and Asia are classified as types IV to VI, moderate to dark brown skin.
THE ORIGIN OF SKIN TONE
The original evolution of skin tone had to do with the individual’s geographic relationship to the equator. The function of melanin is to protect the skin from the ultraviolet rays of the sun. As populations migrated north and south from the equator, their skin tones generally got lighter. The closer they lived to the equator, the darker their skin tone remained.
When those who have less melanin in their natural skin tone expose their skin to high levels of ultraviolet rays, by spending lots of time in the sun or regularly using tanning beds, more melanin is produced and the skin gets darker – an effect called tanning. Along with darkening the skin, this exposure also increases the chances of developing skin cancers.
Darker skin may be more protected from sun damage because of the naturally-higher levels of melanin, but sun damage can still occur. Protective clothing and sunscreen should be part of the skin care regimen of those with darker skin to prevent damage that could eventually lead to skin cancer or other conditions like melasma.
MELASMA IN DARKER SKIN
Skin that is naturally darker has the advantage of some natural sun protection and shows slower signs of aging, but is also susceptible to blotchy skin discoloration. Melasma, also known as hyperpigmentation, dyschromia, chloasma, age spots, and liver spots, is an alteration in the color of the skin due to an increase in melanin. Melasma often occurs in a spotty pattern on the skin as it ages, although it can occur at younger ages, too. It is a more frequent problem in women, especially those with darker skin tones. Although not dangerous or life-threatening, melasma is a common cosmetic concern.
This increase in melanin can also be initiated by pregnancy, birth control pills, injury to the skin such as cuts and burns, or post-inflammatory hyperpigmentation from acne. In some cases, the overuse of hydroquinone will create exogenous ochronisis, which is a type of hyperpigmentation across the face and other areas that is different from melasma. Melasma can be minimized with a good skin care regimen and the continual use of high SPF sunscreen.
Two major considerations in the treatment of melasma are the skin type (normal, oily, dry, or combination) and the color of the skin. It is better to use a mild alpha hydroxy acid product. If a strong peeling agent is going to be used to try to eliminate melasma or hyperpigmentation, the skin needs to be pre-treated for a minimum of 12 weeks with topical treatment starting again five days after the peel. Pre-treating longer than 12 weeks, and with products that are not as strong, is safer and more effective than a quick fix. Peeling agents such as phenols should be avoided because they can cause worse hyperpigmentation than they seek to treat.
Hyperpigmentation is found mostly on the face and hands, although, since it is exacerbated by the sun, it can be found on any sun-exposed areas. Although there is no cure for hyperpigmentation, it can be minimized with careful attention to staying out of the sun, protecting the skin with a minimum of a SPF 15 used daily, and treating with the appropriate products. If outdoor activities are a part of the client’s lifestyle, then a higher SPF is necessary.
Acne in skin of color presents a challenge as well. Most of the time, when there is a blemish, hyperpigmentation will be present. Some skin care products used to control acne contain benzoyl peroxide, an ingredient that will turn dark skin darker. Educate the client about their skin condition and the different therapies available that can clear acne. Work up a treatment program so that the client understands the amount of time that it takes to clear acne and minimize hyperpigmentation.
ALPHA HYDROXY ACID FOR DARKER SKIN
Many common skin products containing glycolic acid can worsen the problems of darker skin. Alpha hydroxy acid products with concentrations higher than 15 percent may also have detrimental effects on skin of color. However, milder alpha hydroxy acid products, like mandelic acid, are safe for use on all skin tones. Mandelic acid, which is extracted from bitter almonds, gently exfoliates the skin to remove damage and reveal clearer, healthier skin.
Some possible side effects of alpha hydroxy acid products include skin dryness, mild redness, and peeling. These effects can be lessened by a gradual start to using products that contain the ingredient, such as using the product once a day for the first week before increasing to the recommended twice daily. Slowly introducing skin of color to milder alpha hydroxy acids can help eliminate potential side effects.
Mild alpha hydroxy acids can be used to reduce the appearance of fine lines, melasma caused by hyperpigmentation, signs of sun damage, and aging on darker skin.
With proper care, the common problems of darker skin can be managed, minimized, or even eliminated. Skin care professionals can take a proactive approach to preventing problems like acne scarring and sun damage by educating their clients on proper skin care procedures early, before damage begins to occur.