Inflammation from acne blemishes can overstimulate the skin's pigment-producing cells and cause them to create too much melanin. Once the blemishes clear, they frequently leave behind small, dark blotches on the skin that are known as postinflammatory hyperpigmentation. Due to the higher levels of melanin in darker skin tones, people of color are particularly susceptible to the development of post-acne skin discolorations. While these dark spots will fade eventually on their own, several measures can be taken to help speed up the process.

Use an adequate sunscreen. Apply a broad spectrum sunscreen with an SPF of 30 or higher to your face at least 30 minutes before going outside. If you skin is oily, use a sunscreen in gel or spray form that is non-comedogenic, which means that it does not clog pores. The ultraviolet rays of the sun can overstimulate the melanin-producing cells in the skin, which can exacerbate existing skin discoloration issues. Therefore, protecting your skin from the sun is essential.

Avoid benzoyl peroxide. While the antibacterial properties of benzoyl peroxide can help control acne, the medication can also cause dryness and skin irritation. This can worsen postinflammatory hyperpigmentation and lengthen its duration, particularly for people with darker skin tones. The American Academy of Dermatology suggests that you only use benzoyl peroxide if directed to do so by your doctor.

Use a topical retinoid medication to control acne. If you are still experiencing breakouts, talk to your doctor about using a prescription strength topical retinoid, such as tazarotene or tretinoin, to prevent future blemishes. These medications tend to be less irritating to the skin if used as directed, notes the American Academy of Dermatology. Apply a small, pea-sized amount to clean skin on a nightly basis. If redness and irritation do occur, discontinue use and notify your dermatologist.

Use a skin lightening cream, such as hydroquinone, once your acne has cleared. With continued use, hydroquinone lightens skin discolorations by blocking the production of melanin. Look for an over-the-counter serum or cream that contains up to 2 percent hydroquinone, or ask your dermatologist for the prescription strength version which contains up to 4 percent. For the over-the-counter cream, apply small amount to the entire face, once a day after cleansing. Apply the prescription strength medication only to the hyperpigmented areas, once or twice a day. Since hydroquinone can take quite some time to generate results, you may need to use the medication for up to six months.

Undergo microdermabrasion treatments. The microdermabrasion procedure uses abrasive particles to gently scrape away the uppermost layer of the skin, taking with it the excess pigment deposits. Dermatologist Susan Taylor's website, Brownskin, asserts that microdermabrasion is well-tolerated by people with darker skin tones. Budget for a series six to eight of microdermabrasion treatments, spaced every two to four weeks, for best results. As of 2010, microdermabrasion sessions ranged between $75 and $150 each.