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Post-inflammatory hyperpigmentation, erythema and melasma are three different problems

⏱ 2 min read
Quick answer: PIH is brown or grey-brown pigment deposited after inflammation; PIE is pink-to-red discolouration from dilated vessels left behind after inflammation, containing no excess pigment at all; melasma is a chronic, symmetrical pattern driven by hormones, UV, visible light and heat, and it behaves unlike either. They respond to different things, which is why misidentifying yours is the commonest reason a brightening routine goes nowhere. A dermatologist distinguishes them quickly, and melasma in particular benefits from professional input.

PIH is brown or grey-brown pigment deposited after inflammation; PIE is pink-to-red discolouration from dilated vessels left behind after inflammation, containing no excess pigment at all; melasma is a chronic, symmetrical pattern driven by hormones, UV, visible light and heat, and it behaves unlike either. They respond to different things, which is why misidentifying yours is the commonest reason a brightening routine goes nowhere. A dermatologist distinguishes them quickly, and melasma in particular benefits from professional input.

PIH: pigment left behind

After acne, a burn, an ingrown hair or any inflammation, pigment-producing cells can overshoot and leave a brown, tan or grey-brown flat mark. It is common in every skin tone and tends to be more pronounced and more persistent in deeper tones. Depth matters: pigment sitting in the upper layers fades in months, pigment that has dropped deeper can take far longer and responds much less to topical products. Sun exposure darkens it reliably, which makes daily sunscreen the single most useful habit here.

PIE: not pigment at all

Pink, red or purplish flat marks after a spot are dilated capillaries in skin that has been inflamed, not melanin. The check is simple: press the mark or stretch the skin, and if it blanches and briefly disappears, it is vascular. This matters because brightening actives aimed at melanin — arbutin, kojic acid, tranexamic acid — do relatively little for it. PIE generally fades with time provided the spot is not re-inflamed, so the useful interventions are barrier support, sun protection and not picking.

Melasma: a different animal

기미 (gimi) presents as symmetrical, map-like patches on the cheeks, forehead, upper lip or jaw, and it relapses. UV drives it, but so does visible light — which is why tinted sunscreens containing iron oxides are specifically discussed for melasma — and so does heat, meaning saunas, hot yoga and steaming showers can aggravate it independently of light. Hormonal factors are involved. It is realistically managed rather than cured, it recurs, and it responds far better to a dermatologist's plan than to rotating serums.

What all three share

Two things. First, sun protection is non-negotiable in every case: applied properly, reapplied, and supported by hats and shade. Without it, nothing else you do will show. Second, do not re-injure the skin. The classic own goal is escalating exfoliation to speed fading up, which inflames skin and produces more of exactly the mark you are chasing — particularly in deeper tones, where aggressive treatment carries real risk of worsening pigmentation. Slow, gentle and consistent genuinely outperforms fast and harsh.

⚕️ Education only. General information about Korean skincare/aesthetic concepts — not medical advice or a recommendation. Procedures carry risks; always consult a licensed medical professional in person.

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✍️ Written & reviewed by the KoreaPlus Editorial team — dermatologist-informed, cosmetic-science researched & source-cited. Last reviewed: 2026-08-23.

General educational information using cosmetic structure-function wording — not medical advice. Always patch-test new actives. © KoreaPlus.