Post-Acne Marks (PIE and PIH)
Post-Acne Marks (PIE and PIH) — the flat discolored marks that can linger after a breakout heals, distinct from raised or indented scars. Post-inflammatory erythema (PIE) appears as pink or red marks from lingering blood vessels, while post-inflammatory hyperpigmentation (PIH) shows as brown or dark spots from excess melanin.
Key points
- PIE and PIH are changes in color, not texture, so the skin surface remains smooth even though the marks are visible.
- PIE tends to be more common in lighter skin tones, while PIH is more frequent and often longer-lasting in deeper skin tones.
- These marks usually fade on their own over weeks to months, though the process can be slow without treatment.
- Daily sunscreen is essential, since sun exposure can darken and prolong both types of marks, and ingredients like azelaic acid, vitamin C, niacinamide, and retinoids may help speed fading.
Frequently asked
Are post-acne marks the same as acne scars?
No, post-acne marks are flat changes in skin color that typically fade over time, whereas true scars involve permanent changes in skin texture such as indentations or raised tissue. Marks generally resolve on their own, while scars often need procedural treatment.
How can I fade post-acne marks faster?
Consistent daily sunscreen prevents marks from darkening, while ingredients like vitamin C, niacinamide, azelaic acid, and retinoids can support faster fading. Patience is key, as discoloration often takes weeks to months to resolve.
Related topics
This is a foundational entry in the SYNC Skin Encyclopedia and is expanded over time. Educational information only — not medical advice.
