Why Does Hyperpigmentation Last After Acne
After acne heals, many people notice dark spots that stick around for weeks or months. These spots, known as post-inflammatory hyperpigmentation or PIH, happen because your skin makes extra melanin, the pigment that colors your skin, as part of its healing process.
When acne flares up, it causes inflammation deep in the skin. This inflammation acts like a signal to special cells called melanocytes. These cells ramp up melanin production to protect the area from further damage, similar to how skin tans after sun exposure. The more severe the acne, like cystic pimples that go deep under the skin, the stronger this response and the darker the spots left behind.
Unlike actual acne scars, which change the texture of your skin with pits or ridges, PIH is flat. It only affects color. On lighter skin tones, these marks might look pink or red at first, from damaged tiny blood vessels. But on darker skin, they turn brown or black due to the melanin buildup. This difference comes from how skin types handle inflammation.
The spots last because melanin does not fade quickly. Your skin sheds dead cells slowly, and the extra pigment sits in the deeper layers until new skin pushes it out. Sun exposure makes it worse by triggering even more melanin. Picking or squeezing acne spreads inflammation, creating larger or longer-lasting spots.
People with darker skin tones often see PIH more because their melanocytes react stronger to injury. Hormones or certain medications can play a role too, but acne inflammation is the main trigger here. Over time, most spots fade on their own, but it can take three to six months or longer without help.
Sources
https://worldofasaya.com/blogs/acne/post-acne-hyperpigmentation-your-complete-guide
https://www.atlantaskinandaesthetics.com/hyperpigmentation/
https://www.clinicbe.com/skin/acne-pigmentation/
https://www.kavimd.com/effective-treatments-for-hyperpigmentation-how-to-even-skin-tone
https://banish.com/blogs/article/pie-vs-pih-how-to-tell-the-difference
https://www.serenityrejuvenationcenter.com/services/post-inflammatory-hyperpigmentation-pih-treatment-in-seattle/
https://www.youtube.com/watch?v=Ro1j61PZYKQ
