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Post-Inflammatory Erythema: The Red Marks Acne Leaves Behind

By Michael C. · Written and reviewed by Michael C.

Post-Acne Marks · Published 2026-05-26 · 10 min read · 1980 words · Updated 2026-09-08

PIE is flat vascular redness left after inflammation, distinct from pigment-based PIH, and needs calming, not brightening, treatment.

Key takeaways

  • PIE is caused by dilated surface blood vessels, not excess pigment like PIH.
  • The blanch test — pressing a mark to see if it pales — helps tell PIE and PIH apart at home.
  • Pigment-fading products do little for PIE; calming, barrier-focused care works better.
  • Stubborn PIE responds best to professional vascular laser treatment like pulsed dye laser.

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Source: SkinLabs Editorial Team ()

Cover image: Divine Effiong — credit