Anatomy Skin Pigmentation

Skin pigmentation describes the color of the body’s skin, which can be anywhere from pale and slightly pink (due to the concentration of blood in the skin) to extremely dark brown, depending on the amount of melanin a person’s skin contains.

Melanin is the basic component that gives skin, eyes and hair its color. The more melanin a specific tissue has, the darker that organ will be in color.

For example, people with paler skin have a less melanin in their skin than those with tan or darker skin. Similarly, when we tan, the sun’s rays (or rays from a tanning bed) cause cells called melanocytes to increase their production of melanin, causing our skin to take on a more golden to brown hue.

The Causes of Skin Pigmentation

Here are some of the factors that play a role in determining the skin color of different individuals:

  • Gender: Women tend to have less melanin and, therefore, lighter skin than men.
  • Health conditions: The presence of certain health conditions, such as pregnancy, can increase your body’s melanin production, making skin tones darker.
  • Heredity: Your skin color is largely determined by the genetic composition of your parents’ skin pigmentations.
  • Lifestyle: People who spend more time outdoors will be in the sun more, causing their skin to be darker as it produces more melanin overtime.
  • Location: Those who live in sunnier regions will likely have more contact with the sun, causing them to have darker skin pigments.

The Function of Melanin and Skin Pigmentation

Skin, as the largest organ of the body, functions to not only protect us from the elements, but it also:

  • allows us to feel the sensations of hot, cold, pain, pleasure, etc.
  • controls our body temperatures
  • eliminates waste in the form of sweat.

Although researchers are still currently investigating the precise role of the skin’s pigment and melanin, many experts believe that both fall into the protective category, helping to defend out skin from the elements, namely the sun.

Prevailing theories suggest that melanin, which lies in the middle layer of the skin (known as the epidermis), is responsible for absorbing the sun’s harmful rays, such as UVA and UVB rays. By filtering out these dangerous rays, melanin prevents them from penetrating the deeper layers of the skin and causing more damage. As a result, the more melanin a person has, the darker his skin is and the greater natural protection he has against the sun.

However, the natural levels of melanin your skin contains are distinctly different from the melanin it develops as a result of contact with the sun (i.e. the melanin that causes you to tan). In fact, prolonged exposure to the sun and increased production of artificial melanin will, over time, cause the skin to prematurely age.

In severe cases, melanin stops being effective at absorbing the sun, allowing the UVA and UVB rays to penetrate to the skin’s deeper layers. Over time, this can lead to serious health complications, such as potentially fatal forms of skin cancer.

Skin Pigmentation Disorders

Unfortunately, not everyone has skin pigments and melanin levels that fall within a healthy range. Here are two of the most common skin pigmentation disorders:

  • hyperpigmentation: This skin problem, that can affect people of any ethnicity, results when patches of the skin appear darker than other areas of normal pigmentation. Those suffering from hyperpigmentation may have symptoms that include liver spots and blotchy areas of darker skin. If no more serious underlying medical condition is causing hyperpigmentation, laser treatments are sufficient to resolve this skin problem
  • hypopigmentation: In contrast to hyperpigmenation, hypopigmentation results from a lack of melanin producing cells (known as melanocytes). Those with this skin condition typically have abnormally pale skin. For example, albino people suffer from hypopigmentation.

    Treatment for hypopigmentation depends on the area that is affected (Remember the eyes and the skin can suffer from lack of melanin). While surgery is available for hypopigmentation of the eyes, at this time taking measures to protect oneself from sun damage is the best treatment for hypopigmentation of the skin.

Resources

American Osteopathic College of Dermatology (n.d.). Hyperpigmentation. Retrieved October 31, 2007 from the AOCD Web site: http://www.aocd.org/skin/dermatologic_diseases/hyperpigmentation.html.

Skin Care Information (n.d.). Skin Function. Retrieved October 31, 2007 from the Skin Care Information Web site: http://www.skin-care-information.org/how-the-skin-works.html.

WiseGeek (n.d.). What is Melanin? Retrieved October 31, 2007 from the WiseGeek Web site: http://www.wisegeek.com/what-is-melanin.htm.