Did you know that pigmentary disorders are the third most common type of dermatologic disorder? (J Cutan Aesthet Surg. 2013)
A skin pigmentation disorder refers to the changes in skin color based on the amount of melanin, a group of pigments produced by cells called melanocytes in the lower level of the epidermis. There are three main types of melanin: eumelanin, pheomelanin, and neuromelanin. In humans, eumelanin is the most abundant, and along with pheomelanin, it is the pigment that determines the color of skin and hair.
After damage from UV radiation, melanin is produced and causes the skin to visibly tan. Melanin is one of the skin’s natural defense mechanism against sun damage because it can effectively absorb light and dissipate over 99.9% of absorbed UV radiation. (Photochem Photobiol. 2004)
This article will specifically cover the pigmentary disorder known as hyperpigmentation, which is the darkening of an area of skin due to an excessive or irregular production of melanin.
What causes hyperpigmentation?
There are two broad ways to categorize cases of hyperpigmentation: localized or diffuse.
Localized hyperpigmentation can be caused by multiple factors including sun damage, inflammatory conditions, acne, and injuries to the skin.
Diffuse hyperpigmentation is typically associated with metabolic causes, certain medications, malignancy, or autoimmune or infectious etiologies. (J Clin Aesthet Dermatol. 2014) It is important to share your full medical history with your dermatologist since the cause of diffuse hyperpigmentation may be associated with malignancy, an underlying disease, or a medication you are taking. Addressing any underlying conditions causing your pigmentary disorder would be the first step of treatment.
Although the pathogenesis for hyperpigmentation is not fully understood, it is known that both localized and diffuse disorders involve inflammatory mediators such as prostaglandins and leukotrienes. These mediators stimulate epidermal melanocytes, thus disrupting the skin’s basal layer and causing a dermal deposition of melanin. (J Clin Aesthet Dermatol. 2014)
Wearing sunscreen on all sun-exposed skin on a daily basis is the easiest way you can prevent the future development of dark spots as well as reduce your risk of getting skin cancer.
It is highly recommended that patients use sunscreens that contain physical blockers of UV radiation, such as titanium dioxide and zinc oxide.
On the other hand, chemical sunscreens, which contain organic compounds such as oxybenzone, octinoxate, octisalate and avobenzone, can also be effective at protecting the skin from UV damage. However, there have been rare cases of these sunscreens causing allergic contact or irritant contact dermatitis in patients with darker skin, which itself can lead to post-inflammatory hyperpigmentation. (J Clin Aesthet Dermatol. 2014)
Whether you choose to wear a physical or chemical sunscreen to protect your skin, ensure that it is at least SPF 30. Wear it every single day, rain or shine, and reapply every 2 hours to help prevent future spots.
Lastly, it is recommended for patients to practice UV avoidance through the use of physical barriers, such as wearing hats and clothing that reduces sun exposure.
Topical treatment of hyperpigmentation
The gold standard treatment option for localized hyperpigmentation in terms of topical formulations is hydroquinone. According to the American Osteopathic College of Dermatology, hydroquinone lightens the skin by inhibiting the enzymatic conversion of tyrosine to DOPA (dihydroxyphenylalanine) in melanocytes, which results in the desired chemical reduction of melanin. Ultimately, this leads to a decrease in the number of melanocytes and decreased transfer of melanin, resulting in lighter skin.
Hydroquinone has been formulated in some OTC solutions and creams in the strength of 2%, and is available as a 4% prescription cream. There is also a cream called Tri-Luma that combines hydroquinone with tretinoin (a retinoid) and fluocinolone acetonide (a corticosteroid that decreases inflammation).
Besides hydroquinone, topical treatment of hyperpigmentation can include the use of retinoids (i.e. tretinoin, tazarotene) and azelaic acid. New therapies that are being researched in numerous case reports and studies include zinc, arbutin, kojic acid, vitamin C based compounds, and green tea extracts. (J Clin Aesthet Dermatol. 2014)
Procedures to treat hyperpigmentation
In addition to prescription creams, dermatologists also provide treatment options for hyperpigmentation that include chemical peels as well as laser rejuvenation.
A popular cosmetic treatment for a wide range of skin concerns, including hyperpigmentation, is the Vitalize Peel®. It contains a blend of alpha- and beta-hydroxy acids, as well as resorcinol and retinoic acid, to even skin tone and texture and give your complexion a glow.
In regards to laser rejuvenation, one type of laser that can be used to reduce or eliminate the appearance of dark spots is IPL, or Intense Pulsed Light. IPL treatment uses intense pulses of light to improve the appearance of sun damage, acne scars, and other skin imperfections. While you may see noticeable results after one treatment, most women and men achieve maximum results after a series of treatment sessions. IPL is a non-invasive procedure that requires little to no downtime afterward.
Another laser used to treat hyperpigmentation is the PicoSure® FOCUS™, an FDA-approved aesthetic picosecond laser that is the first of its kind. It is also a non-invasive treatment that typically only takes a few minutes to complete with little to no downtime.