What exactly causes brown spots?
Even the smallest irritation, like a bug bite, can cause a brown spot to occur on the skin. This happens when dark skin is inflamed or injured, and a condition called PIH, or post-inflammatory hyperpigmentation, occurs. The underlying reason for PIH, according to Dr. J. Leffell of the Yale School of Medicine, is an increase in the transfer of melanin molecules from the bottom layer of the skin (the dermis) to the top layer of the skin (the epidermis). When the dermis is also injured, pigmentation containing scavenger cells, or melanophages, set up house in the dermis for a long time, resulting in discoloration. These brown spots can last anywhere from a few weeks to a year.
Using Skin Bleaching Products
Today's treatments for dark spots most commonly contain hydroquinone (HQ). By blocking the action of the enzyme tyrosinase, hydroquinone stops the production of melanin. HQ products, available in creams, gels or liquids, are available in 1 to 2 percent strengths over the counter. You can begin using over-the-counter products for several months, according to Dr. Deborah Simmons, a New York dermatologist. However, if you have not seen your desired change in skin tone after a few months of use, it's time to see a doctor who will prescribe a higher concentration of hydroquinone.
Products used to fade dark spots should be used sparingly and applied carefully. Hydroquinone will fade all skin, not just the dark patches, so it's important to make sure the product stays only on the area you want to treat. Some products come with a spatula for this purpose. Many women apply the product with their fingertip, but a concealer brush would allow you to paint over the dark area more precisely.
Bleaching products are typically applied once in the morning and again in the evening to freshly-cleansed skin. Follow the directions that come with the product carefully.
Make sure you use a sunscreen with an SPF15 or higher on areas of the skin you are bleaching. Ultraviolet rays will further darken brown spots.
Preventing Brown Spots
Pimples, rashes and even mosquito bites, can cause dark skin to mottle. These darker patches are called post-inflammatory hyperpigmentation (PIH) and are caused by over-active pigment cells. To prevent PIH, dermatologists caution to treat skin gently.
For African-American skin, acne medications must be used judiciously, perhaps even avoided. Benzoyl peroxide, the primary ingredient in most acne medications, can be irritating. Another caution: Vigorously exfoliating or rubbing the skin may irritate blemishes and increase your chances of getting PIH. Some oral antibiotics, including tetracycline, have been linked to diffusing hyperpigmentation on the face and neck. Discuss alternatives with your doctor.
Other Treatments for Brown Spots
In addition to using hydroquinone to bleach dark spots, a dermatologist may recommend azelaic acid or Retin-A, a drug based on a vitamin A derivative. Azelaic acid works by blocking the skin's production of tyrosinase, turning off the skin's ability to produce pigment cells. Dr. Simmons says science is not sure exactly how Retin-A inhibits melanin production, but dermatologists know that it reduces dark spots. These treatments can only be prescribed by a physician, and following the prescription’s directions is extremely important.