The color of human skin is partly determined by specialized cells in the skin called melanocytes. One important job of melanocytes is to make a brown pigment called melanin. The amount of melanin produced by melanocytes varies across individuals with lighter and darker skin color. Conditions that result in either darkening or lightening of the skin are known as pigmentary disorders.
Pigmentary disorders are a common concern, particularly for persons with skin of color. In fact, numerous studies have showed that disorders of pigmentation are amongst the most common reason for visiting a dermatologist.
Post-inflammatory hyperpigmentation (PIH), the most common pigmentary abnormality, is discoloration that is left on the skin after an underlying skin rash or bump that has healed. Common conditions such as eczema, acne, and psoriasis can all result in PIH. While PIH can happen in all skin tones, it is particularly problematic and more apparent in individuals with darker skin. The distribution of the dark spots follows that of the underlying skin condition. The shades of the hyperpigmentation can vary from light brown, to dark brown to blue and gray.
PIH is difficult to treat. Current treatment options include topical preparations which are available in over the counter or prescription strength, chemical peels, and laser treatments. Topical creams work in various ways to interfere with the amount of pigment production in the skin. They usually include one of the following ingredients:
- 2-4% hydroquinone
- Topical corticosteroids
- Azelaic acid
- Kojic acid
While there is no known cause for PIH, or why certain people are more prone to its development you can take measures to avoid prolonging the condition. Avoiding the sun is one measure, as it can aggravate symptoms and prolong the healing process.
Studies show that sunlight can worsen certain forms of hyperpigmentation, therefore wearing a broad-spectrum sunscreen is a very important part of treatment. Sunscreen should be “broad spectrum” and have a sun protective factor (SPF) of at least 30. You should apply sunscreen daily at least 15 minutes before going outdoors and reapply every two hours.
Lastly, patience is key. Post-inflammatory hyperpigmentation (PIH) can take months, even years for normal pigment to be restored back to its desired level.
Your dermatologist can help determine the best treatment plan for you.
About Dr. Valerie M. Harvey, MD, MPH
Dr. Harvey is located in Newport News at the TPMG Hampton Roads Center for Dermatology.