What Is Post Inflammatory Erythema After Acne
After acne clears up, many people notice flat red or pink spots on their skin where pimples used to be. These spots are called post inflammatory erythema, or PIE for short. PIE is not a real scar that changes the texture of your skin. It is just leftover redness from the inflammation caused by acne.[1][3]
PIE happens when the tiny blood vessels right under the skin get damaged or stretched out during an acne breakout. The inflammation from pimples makes these capillaries dilate, or widen. Even after the pimple heals, the vessels stay a bit open, leaving behind those red, pink, or sometimes purple marks. This is common in people with lighter skin tones.[1][3]
You might see PIE on your cheeks, forehead, or chin, right where the acne was. The spots are flat and do not feel raised or pitted. They can last for weeks or months, but they usually fade on their own over time as the blood vessels heal.[1]
PIE is different from another mark called post inflammatory hyperpigmentation, or PIH. PIH shows up as brown or dark spots from extra pigment made by the skin. PIE is all about the blood vessels, not pigment.[1]
To help PIE fade faster, protect your skin from the sun with sunscreen. Sun can make the redness worse or last longer. Gentle skin care products that calm inflammation, like those with niacinamide or azelaic acid, may help too. If the marks bother you a lot, a dermatologist can suggest treatments like lasers to target the blood vessels.[1]
Sources
https://www.kins-clinic.com/blogs/what-are-the-main-acne-scar-types-a-skin-friendly-guide-with-treatment-options
https://pmc.ncbi.nlm.nih.gov/articles/PMC12691598/
https://www.amoils.com/pages/acne-scars-pictures
https://www.dermasence.com/my-skin/indication/skin-redness
