Long lasting red acne marks, known as post-inflammatory erythema, happen when inflammation from acne damages tiny blood vessels under the skin. These marks stay red or pink for months or even years because the vessels take a long time to heal fully.
Acne starts with pimples, pustules, or cysts that cause swelling deep in the skin. This swelling irritates the blood vessels, leaving them dilated and visible after the pimple goes away. The deeper the acne goes into the skin layers, the worse the damage and the longer the redness lasts.
Certain types of acne lead to these stubborn marks more than others. Cystic or nodular acne creates strong inflammation that spreads far and heals slowly. On areas like the back or chest, where oil glands are dense, acne flares up often and hits harder, making red marks tougher to fade.
Picking or scratching the spots makes things worse. It adds more injury, keeps inflammation going, and turns simple redness into lasting damage.
Skin type plays a big role too. Sensitive skin reacts with extra inflammation, so red marks linger longer. People with lighter skin tones often see these red marks more clearly because their skin shows vessel changes easily.
Sun exposure can make the problem stick around. UV rays slow healing by breaking down skin repair proteins and keeping blood vessels irritated.
Genetics also matter. Some people heal with more redness due to how their body handles inflammation and collagen repair.
Delaying treatment keeps acne active longer, which builds up more vessel damage over time. Early care reduces the chance of long red marks forming.
Sources:
https://www.london-dermatology-centre.co.uk/blog/acne-scarring-back-chest-treatment/
https://www.kins-clinic.com/blogs/what-are-the-main-acne-scar-types-a-skin-friendly-guide-with-treatment-options
https://www.pristyncare.com/consult/acne-scars-for-years-is-complete-skin-clearance-possible/
https://worldofasaya.com/blogs/skin-types/skin-type-acne-marks-what-you-must-know
https://www.mesoestetic.com/blog/acne-scars/
https://artofskincare.com/blogs/learn/how-to-treat-post-inflammatory-hyperpigmentation-at-home
https://slmdskincare.com/blogs/learn/the-5-kinds-of-acne-scars-how-to-treat-each-type
