PIH vs PIE: Brown vs Red Acne Marks Explained

A breakout clears, but the reminder stays behind — sometimes a brown shadow, sometimes a red-pink flush. These post-acne marks look similar in a mirror, yet they are two different things happening in two different layers of your skin. Telling brown acne marks from red ones is the single most useful step, because it changes everything about how each is handled.

Two people can have the exact same pimple in the exact same spot and heal with completely different reminders. One is left with a coffee-coloured smudge; the other with a rosy patch that looks like the breakout never fully left. The difference isn't luck — it's which repair response the skin defaulted to. When skin becomes inflamed, it can ramp up melanin (its natural pigment) or leave the tiny blood vessels near the surface dilated and visible. The first shows brown; the second shows red. Everything else flows from that single fork in the road.

What Causes PIH?

Post-inflammatory hyperpigmentation is the skin's pigment response to inflammation. When an acne lesion — a comedone, papule or pustule — becomes inflamed (or when a bite, burn or even a cosmetic procedure irritates the skin), the inflammatory response releases signalling molecules called cytokines. These can switch on melanocytes, the pigment-producing cells of the epidermis, prompting them to release extra melanin into the area.

Where that pigment lands matters. When it stays in the upper layer (the epidermis), PIH tends to look brown and fades comparatively faster. When inflammation reaches deeper and pigment settles into the dermis, it can look greyer or blue-brown and is far more stubborn. Sun exposure (UV radiation), picking, and repeated breakouts all keep the pigment pathway switched on — which is exactly why post-acne pigmentation so often outlasts the acne itself.

What Causes PIE?

Post-inflammatory erythema is the skin's vascular response. Inflammation dilates — and can subtly damage — the small blood vessels (capillaries) in the upper dermis. Once the acne lesion heals, those vessels can stay widened and visible, leaving a flat pink-to-purple mark. Because it's essentially blood showing through the skin, PIE reads more clearly on lighter skin tones.

PIE is a relatively modern term: it was formally introduced to the dermatology literature in 2013, specifically to separate these red vascular marks from brown melanin marks so that each could be understood on its own terms. That distinction is the whole point of this article — the two respond to completely different logic.

PIH vs PIE, Side by Side

Here's the same information split cleanly down the middle. Read the colour that matches your mark.

PIH vs PIE vs True Acne Scars

Here's the distinction that saves people the most worry: PIH and PIE are flat colour changes, not scars. A true acne scar is a change in the skin's texture — raised (keloid or hypertrophic) or depressed (atrophic: boxcar, rolling or ice-pick). Scars involve altered collagen and generally don't resolve on their own, whereas flat marks usually fade with time and care.

The quick check: catch the mark in side lighting or run a fingertip over it. If it has depth or elevation, it's textural — a scar. If it's smooth and level with the skin and the only difference is colour, it's PIH or PIE.

Can PIH or PIE Become Permanent?

For most people, no — because both are flat colour changes rather than structural damage. PIE most often settles over months. PIH is slower and can take a year or longer, with deeper dermal pigment lasting longer still. What turns a temporary mark into a very long-lasting one is usually repeated inflammation in the same spot, ongoing sun exposure, and picking. If what you're seeing is a textural dent or bump rather than a flat discoloration, that's a true scar — a separate issue from PIH or PIE.

Can PIH and PIE Occur Together?

Yes — very commonly. Across a mixed area of active and healing breakouts, it's normal to see brown and red acne marks side by side, and a single mark can even carry both a pigment and a vascular component at once. This is another reason the simple press-test is handy: it helps you sort which part of a mark is which, so your care can match.

Skin Tone and Which Mark You Get

If you have medium-to-deep skin, PIH is likely the mark you know best — and there's a clear reason. Deeper tones carry more reactive melanocytes, so the skin's instinctive answer to inflammation is to produce pigment. That's the same protective machinery behind richer skin's natural resilience; it simply also means marks arrive as brown pigment rather than red vessels.

For Fitzpatrick III–VI skin, two habits carry outsized weight: calming inflammation early (so less pigment is triggered) and daily sun protection (because UV deepens and prolongs existing PIH).

Can You Prevent PIH and PIE?

You can't guarantee it, but you can meaningfully lower the odds — and prevention comes down to one idea: less inflammation, less mark. In practice that means treating breakouts gently and early rather than aggressively, never picking or squeezing, wearing daily broad-spectrum SPF (non-negotiable for pigment-prone skin), supporting the skin barrier, and resisting the urge to over-exfoliate — harsh routines create the very inflammation that leaves marks behind. For deeper skin especially, gentle, consistent acne management is the most powerful PIH-prevention tool there is.

Common Mistakes That Make Marks Worse

Most of what prolongs a mark is well-intentioned over-effort. The usual culprits:

How Each Mark Is Usually Approached

General Education

Because PIH and PIE start in different layers, they respond to different strategies. The notes below are general skin-science education, not a treatment plan — a dermatologist is the right person to build one for your skin.

For Brown Marks (PIH)

The pigment conversation usually centres on gentle, consistent surface renewal plus daily sun protection. Mild exfoliating acids — AHAs, BHAs and PHAs at low, well-formulated strengths — are commonly discussed for supporting the skin's natural shedding over regular, repeated use. Ingredients such as niacinamide and azelaic acid appear frequently in the research literature on post-acne pigmentation. Stronger agents like prescription tyrosinase inhibitors (for example, hydroquinone) belong firmly in dermatologist-supervised territory and are not something to self-prescribe from an unregulated cream. Above all, PIH is a game of patience plus SPF, not force.

For Red Marks (PIE)

Because PIE is vascular, the priority is usually not irritating it further. A calm, barrier-supportive routine gives dilated vessels time to settle, and gentle hydration keeps recovering skin comfortable. Persistent or spreading redness is worth showing to a dermatologist, who can distinguish PIE from other causes of facial redness and, for stubborn cases, discuss in-clinic vascular options.

When Should You See a Dermatologist?

Most post-acne marks resolve with patience and gentle care. Book a professional review if a mark hasn't shifted over several months, is spreading or very dark, looks textural (a possible scar), or is causing you real distress. A dermatologist can confirm what you're seeing, rule out look-alikes such as melasma or other causes of facial redness, and discuss options — from prescription topicals to peels and lasers (for example, pulsed-dye laser for red marks or pigment-targeting devices for stubborn PIH). Getting the diagnosis right first is what makes any approach work.

Frequently Asked Questions

Keep Reading

Build the full picture across the Boldpurity Skin Science library: our companion guide on erythematous scars (red marks in depth), the melanogenesis explainer on how melanin is made, the hyperpigmentation guide, and the practical basics: the acne guide, skin barrier guide, sunscreen (SPF) guide, ingredient explainers on AHAs, BHAs, PHAs and niacinamide, plus the sensitive skin guide.

Individual results and healing patterns vary. Persistent, spreading, changing or textural marks should be assessed by a qualified dermatologist, who can confirm what you're seeing and recommend an approach suited to your skin.