How Sun Exposure Darkens Acne Scars
Acne scars often look like flat dark spots on the skin, known as post-inflammatory hyperpigmentation or PIH. These spots form when acne inflammation causes the skin to produce extra melanin, the pigment that gives skin its color.[1][3][7]
When you get a pimple, the body’s healing process ramps up melanin in that area to protect against damage. This leaves behind a temporary dark mark after the pimple heals. Unlike indented or raised scars from collagen loss, PIH is just discoloration and can fade on its own over months.[1][3]
Sun exposure makes these dark spots worse. Ultraviolet rays from the sun signal the skin to make even more melanin as a defense. This extra pigment piles onto the existing dark mark, turning it darker and making it last longer.[1][3][4]
UV radiation also breaks down collagen in the skin. Collagen helps scars heal and keeps skin smooth. When sun damages it, the area around the scar weakens, making the dark spot stand out more.[1][2]
People with darker skin tones see this effect more because they naturally have more melanin, which responds strongly to sun.[3]
To stop this darkening, apply broad-spectrum sunscreen with SPF 30 or higher every day, even indoors or on cloudy days. Reapply every two hours if outside. Mineral sunscreens with zinc oxide work well for acne-prone skin.[1][2][3]
Sources
https://www.kins-clinic.com/blogs/what-are-the-main-acne-scar-types-a-skin-friendly-guide-with-treatment-options
https://www.london-dermatology-centre.co.uk/blog/acne-scar-recurrence-maintenance/
https://artofskincare.com/blogs/learn/how-to-treat-post-inflammatory-hyperpigmentation-at-home
https://www.augustaaesthetic.com/pigmentation-sun-spot-treatment/
https://www.oreateai.com/blog/dark-spots/
https://evenlyclinic.com/blog/pigmentation/best-treatment-for-pigmentation-on-face/
https://worldofasaya.com/blogs/acne/essential-checklist-preventing-skin-scarring-now
https://consciouschemist.com/blogs/good-skin-blog/how-to-treat-acne-without-dark-marks-or-scars
