When you have a severe acne blemish, a scar can remain even if the blemish has gone away. This condition is known as post-inflammatory hyperpigmentation, according to Derma Doctor. Although dark acne spots are not actually scars, they can be just as permanent. If your dark acne spot has lasted longer than a year, you may want to treat it.
Apply lemon juice to the acne spot twice daily to lighten the spot. Soak a cotton swab or cotton ball in lemon juice and then dab this on the acne mark. After leaving on for 10 minutes, rinse the lemon juice away.
Apply a scar treatment cream to reduce inflammation and redness that can contribute to dark acne spots. This may require three applications per day over the course of several weeks, according to Derma Doctor.
Apply a prescription cream that consists of hydroquinone and glycolic acid. The hydroquinone helps to bleach the area that's discolored, while the glycolic acid encourages cell turnover and skin healing, according to Derma Doctor.
Exfoliate weekly. This will remove dead skin cells and lighten the skin. You can purchase an exfoliant or make your own. Mix 1 teaspoon baking soda with 2 teaspoons filtered water to make a paste. Massage this paste on the acne scar for one to two minutes and then rinse.