Post-Inflammatory Erythema (PIE)
Post-Inflammatory Erythema (PIE) — a form of lingering pink, red, or purple discoloration that remains after inflammation, most often from acne, and reflects dilated or damaged small blood vessels near the skin surface rather than excess pigment. It is typically most visible in lighter skin tones and often blanches, or briefly lightens, when pressed.
Key points
- PIE stems from capillary damage and dilation during inflammation, distinguishing it from melanin-based marks like PIH.
- Avoiding picking and controlling active breakouts early helps limit its formation.
- Consistent sun protection can prevent the marks from becoming more noticeable and support gradual recovery.
- Ingredients such as niacinamide and gentle barrier-supporting formulas are often used, while in-office vascular lasers are sometimes considered for persistent cases.
Frequently asked
How can I tell PIE from PIH?
PIE appears pink to red and usually blanches when you press on it, while PIH appears brown or tan and does not fade under pressure.
Does PIE go away on its own?
It often fades gradually over weeks to months as the small blood vessels recover, though timelines vary from person to person.
Related topics
This is a foundational entry in the SYNC Skin Encyclopedia and is expanded over time. Educational information only — not medical advice.
