hyperpigmentation

We can face it; acne is already enough of a pain. But for those with darker skin, that struggle begins once the blemishes leave. In most cases, they don’t vanish entirely; they sometimes leave behind dark marks that can take months or even years to fully fade. The formal medical name for these markings is post-inflammatory hyperpigmentation (PIH), and it’s seen more frequently in those with darker skin tones.

What is PIH, and why does it occur?

Then why do these marks take longer to fade away, even for individuals blessed with melanin-rich skin? Well, it all boils down to how sensitive your skin is. In other words, when you get a pimple, it means that your skin is inflamed. In response, it prevents similar damage from happening (for a little while at least) by increasing the production of melanin, which is essentially the pigment that gives your skin its color. People with darker skin have melanin-producing cells that are more active, meaning that they tend to have darker patches that last longer when inflammation occurs.

How PIH looks different on darker skin

PIH generally appears red or pink on lighter skin and usually fades sooner. On darker skin, though, those same marks will show up brown or purple to gray and turn into more internalized as well. These can last for much longer, especially if not treated well or are irritated further.

The problem with dermatology representation

The representation of skin color in dermatology has a big gap currently. This is because most medical resources — especially textbooks and training materials, and also skincare advertisements — show acne and pigmentation concerns on predominantly fair skin types, which is one of the reasons it remains an unmet need. And because of this, patients and doctors have less experience with how these disease processes look in brown skin. You may have never seen how it appears on deeper skin tones if you only experience red acne on pale skin. That could lead to real issues like not receiving the required care or attention.

What you can do about it

If you have dark skin, the good news is that PIH can be treated.

By following a regular skin care routine, you can see dark spots fade back, and it helps minimize their appearance. Azelaic acid, niacinamide, or kojic acid are some of the key ingredients to look out for. And don’t forget sunscreen! While darker skin does not burn as easily, it can still be damaged by the sun, which only serves to exacerbate PIH. Also, be sure not to use harsh scrubs or over-exfoliate since it may aggravate the skin and make things worse. If possible, go to a dermatologist who knows how to treat PIH in the same skin color. They will tell you what is best for your skin type and will guide you to the best treatment to have.

Final thoughts

After all, acne marks on darker skin are completely normal and easily treatable. Where it is not okay, however, is when the absence of representation in skincare and dermatology gives way to feeling ignored if you have darker skin. Everyone deserves to be seen, acknowledged, and cared for. Your skin experiences count. This is your chance to have your say!

References

“Hyperpigmentation.” Cleveland Clinic, Cleveland Clinic, 7 Oct. 2021, my.clevelandclinic.org/health/diseases/21885-hyperpigmentation.

Fisher, Jennifer. “Demystifying Hyperpigmentation: Causes, Types, and Effective Treatments.” Harvard Health Publishing, 11 Mar. 2024, www.health.harvard.edu/diseases-and-conditions/demystifying-hyperpigmentation-causes-types-and-effective-treatments.

Ludmann, Paula. “How to Fade Dark Spots in Darker Skin Tones.” American Academy of Dermatology, 10 Mar. 2025, www.aad.org/public/everyday-care/skin-care-secrets/routine/fade-dark-spots.

Markiewicz, Ewa, et al. “Post-Inflammatory Hyperpigmentation in Dark Skin: Molecular Mechanism and Skincare Implications.” Clinical, Cosmetic and Investigational Dermatology, vol. 15, 25 Nov. 2022, pp. 2555–2565, Dove Medical Press, doi:10.2147/CCID.S385162. PubMed Central, PMC9709857.

Veazey, Karen. “What to Know about Hyperpigmentation on Dark Skin.” Medical News Today, 21 Sept. 2023, www.medicalnewstoday.com/articles/hyperpigmentation-black-skin.

What causes pigmentation?

Responsible for providing color to our skin, hair, and eyes, melanin is an essential, naturally produced pigment that our body–and most organisms— is constantly producing. Our natural skin tone is largely accredited to our genetically determined melanin production rate, which vastly varies across ethnicities. Inhabitants of regions with more intense UV radiation have evolved to develop genetic mutations that increase their melanin production and thus have darker skin tones, whereas people in lower UV regions have lighter skin tones. The process of melanin production—otherwise known as melanogenesis—entails the conversion of tyrosinase—a natural enzyme—into melanin.

Simplified pathways of tyrosine-derived melanin synthesis showing... | Download Scientific Diagram — Process of Melanin Synthesis
(ResearchGate)

How does UV radiation influence melanin production?

As a defense mechanism against UV radiation, the skin initiates melanogenesis. Melanin then transfers to keratinocytes—the cell that produces keratin, an essential protein in the epidermis—where the melanin internally absorbs UV rays and reduces DNA damage. However, if the skin receives excessive exposure to UV radiation—without sun protection—the melanin will eventually fail to provide skin protection, leading to sun damage and, soon enough, hyperpigmentation. Although tyrosinase production is also largely influenced by genetics and exposure to UV radiation, tyrosinase, and melanin production can be reduced by tyrosinase inhibitors.

What are tyrosinase inhibitors?

Whether found synthetically in ingredients like azelaic acid or naturally in ingredients like aloe vera, tyrosinase inhibitors are widely used to even out skin tone by blocking tyrosinase activity during catalytic reaction, thereby reducing melanin production and, in some cases, breaking down and degrading pre-existing melanin. Their versatility makes them a key component in the treatment of hyperpigmentation, melasma, and age spots. While different tyrosinase inhibitors function differently, they ultimately yield the same results—reduced melanin synthesis and a more even complexion. Here are some examples of tyrosinase inhibitors with varying potency.

Niacinamide: Although not technically a tyrosinase inhibitor, niacinamide Inhibits melanosome transfer—the process of turning melanin into a visible pigment. Niacinamide does not alter tyrosinase production, making it a more gentle alternative to typical tyrosinase inhibitors. It can be applied up to twice daily.

Azelaic acid: Inhibits tyrosinase and gently reduces pigmentation by targeting hyperactive melanocytes—cells that produce melanin. Azelaic acid is slightly more potent than niacinamide. It can be applied up to twice daily.

Hydroquinone: Directly inhibits tyrosinase and melanin synthesis. It can be used up to twice a day for 3-6 months as treatment for intense hyperpigmentation or melasma; to avoid irritation, it should not be used any longer, as it is highly potent.

Melanogenesis inhibitors are often confused with tyrosinase inhibitors, and although they yield similar results—reducing pigmentation—tyrosinase inhibitors are a subset of melanogenesis inhibitors, which differ in that they affect melanin synthesis as a whole rather than directly targeting tyrosinase. Alongside just targeting tyrosinase production, melanogenesis inhibitors also promote melanin degradation and target melanogenesis pathways, blocking melanin from transferring to keratinocytes.

Which inhibitor is better?

Although melanogenesis inhibitors target several steps in melanogenesis as opposed to directly targeting tyrosinase activity—as seen with tyrosinase inhibitors—that doesn’t necessarily mean that one is stronger or more effective than the other. In general, melanogenesis inhibitors are preferred for more gradual and long-term treatment for pigmentation, whereas tyrosinase inhibitors are stronger for more rapid pigmentation treatment and results. While both are effective in their own ways, combining these treatments with sun protection, exfoliants, and antioxidants ensures the best results for maintaining an even skin tone and treating hyperpigmentation.

Bibliography

Boissy, R. E. “Melanosome Transfer to and Translocation in the Keratinocyte.” Experimental Dermatology, vol. 7, no. 3, 1998, pp. 143-150. PubMed.

National Cancer Institute. “Melanocyte.” NCI Dictionary of Cancer Terms, n.d., [https://www.cancer.gov/publications/dictionaries/cancer-terms/def/melanocyte](https://www.cancer.gov/publications/dictionaries/cancer-terms/def/melanocyte#:~:text=(meh%2DLAN%2Doh%2D,contains%20the%20pigment%20called%20melanin.).

University of Rochester Medical Center. “What Is Skin Pigmentation?” Health Encyclopedia, n.d., https://www.urmc.rochester.edu/encyclopedia/content?contenttypeid=85&contentid=p01359.

Costin, G. E., and V. J. Hearing. “Human Skin Pigmentation: Melanocytes Modulate Skin Color in Response to Stress.” The FASEB Journal, vol. 21, no. 4, 2007, pp. 976-994. PMC.

Burkhart, C. G., and H. R. Burkhart. “Hydroquinone.” StatPearls, StatPearls Publishing, 2019. NCBI.

Pillaiyar, T., M. Manickam, and V. Namasivayam. “Skin Whitening Agents: Medicinal Chemistry Perspective of Tyrosinase Inhibitors.” Journal of Enzyme Inhibition and Medicinal Chemistry, vol. 32, no. 1, 2017, pp. 403-425. PMC.

Chang, T. S. “Natural Melanogenesis Inhibitors Acting Through the Down-Regulation of Tyrosinase Activity.” International Journal of Molecular Sciences, vol. 10, no. 6, 2009, pp. 2440-2475. PMC.

Sasaki, M., K. Hasegawa, and Y. Takahashi. “Recent Advances in Skin Lightening Agents: A Comprehensive Review.” Journal of Dermatological Science, vol. 110, no. 1, 2023, pp. 12-24. PMC.

Tag: hyperpigmentation

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