The melanin in skin of color provides a certain amount of protection from ultraviolet radiation from the sun, and is partly responsible for skin that has less signs of premature aging because melanin works to reduce penetration of UV rays into the skin, protecting the cells and DNA.
Unfortunately melanin also provides a bit of a disadvantage. Skin of color is sensitive, easily irritated and more vulnerable to even the simplest of skin injuries and inflammation which can cause an overproduction of melanin and an irregular dispersion of pigment. Dark spots and patches appear from the resulting hypermelanosis, a scientific term for an excessive and abnormal development of melanin in body tissues.
HP is more common in darker skin
Hyperpigmentation can affect the skin of all races, but is more common and at times more severe and longer lasting in darker skin. The degree of pigmentation in the skin, rather than race or ethnicity, may contribute to developing skin discolorations. Still even those of mixed race and that have very light skin should be aware that they too could have a genetic disposition for hyperpigmentation.
Why it happens
All races have the same number of melanocytes (the cells responsible for melanin production.) Melanocyte cells normally produce pigment evenly across the skin. When these cells are over stimulated, the excess melanin forms deposits on the skin which appear as discoloration in spots, patches or large areas of the skin. Over-stimulation of melanin production can be caused by UV damage, skin trauma and hormonal fluctuations (such as melasma, which can occur during pregnancy, hormone replacement therapy and from the use of oral contraceptives.) The melanocytes in skin of color are more reactive to certain stimuli such as irritation and injury.
When the cause of HP is irritation or inflammation of the skin, the condition is known as post inflammatory hyperpigmentation.
Post Inflammatory Hyperpigmentation can be caused by:
- scratches, burns, bruising
- prescription and OTC topical medications, sensitivity to medications, medications that make the skin photosensitive
- skin care products, irritation from certain skin care practices and even products too harsh for your skin type
- surgery, cosmetic procedures like chemical peels, laser hair removal, microdermabrasion, laser resurfacing procedures
- razor bumps from shaving
- systemic diseases like Addison’s disease
- contact dermatitis and atopic dermatitis/eczema, pityriasis rosacea, pimples, acne, allergic reactions to insect bites
It is also believed that certain plants like parsley, contain psolarens (a photosensitizing agent found in plants) that make the skin more sensitive to sun. PUVA (psoralen and UVA) is often used in the treatment of skin problems like psoriasis, eczema and vitiligo, which is another reason why it is very important to wear sunscreen when undergoing treatments or while taking medications or herbs.
In addition to regularly using sunscreen, early treatment for hyperpigmentation is very important, to avoid creating skin discolorations or making existing discolorations worse. PIH will return if the area is exposed to sunlight and when there is recurring irritation and inflammation.
While waiting for skin discolorations to fade, makeup and concealers can often be used to cover up the dark marks. Read Top 8 Products to Cover Up Hyperpigmentation for more information.