PIH vs PIE: Brown vs Red Acne Marks Explained
A breakout clears, but the reminder stays — sometimes a brown shadow, sometimes a red-pink flush. They look similar in a mirror, and they are two different things happening in two different layers of skin. Telling them apart is the most useful step you can take, because almost everything else follows from it.
Quick Answer
PIH — post-inflammatory hyperpigmentation — is a brown, tan or grey flat mark made of excess melanin. A pigment problem, and the common one on medium-to-deep skin.
PIE — post-inflammatory erythema — is a red, pink or purple flat mark from dilated surface vessels. A vascular problem, and more visible on lighter skin.
Neither is a scar. Both are flat colour changes that usually fade — PIE over months, PIH over a year or more. Press the skin: red briefly blanches, brown doesn't. Though that test is harder to read on deep skin, for reasons worth knowing.
On this page
The background
Two people can have the same spot in the same place and heal with entirely different reminders — one a coffee-coloured smudge, the other a rosy patch. That isn't luck. It is which repair response the skin defaulted to: ramping up melanin, or leaving small surface vessels dilated. The first shows brown, the second red, and everything else follows from that fork.
What Causes PIH
Post-inflammatory hyperpigmentation is the skin's pigment response to inflammation. When a lesion inflames — or a bite, burn or procedure irritates the skin — the inflammatory response releases signalling molecules that switch on melanocytes, prompting them to release extra melanin into the area.
Where that pigment lands matters enormously. Held in the upper layer it looks brown and fades comparatively faster. When inflammation reaches deeper and pigment settles into the dermis, it looks greyer and is far more stubborn.
Sun exposure, picking and repeated breakouts all keep the pigment pathway switched on — which is precisely 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 capillaries in the upper dermis. Once the lesion heals, those vessels can stay widened and visible, leaving a flat pink-to-purple mark. Because it is essentially blood showing through, it reads more clearly on lighter skin.
PIE is a comparatively recent term, introduced to the dermatology literature in 2013 by Bae-Harboe and Graber, specifically to separate red vascular marks from brown melanin ones so each could be understood on its own terms. That separation is the whole point of this article — the two follow completely different logic.
The Press Test, And Its Limits
The five-second check
Press gently with a fingertip or a clear glass, or stretch the skin lightly. A red PIE mark briefly blanches — you are pushing blood out of the vessels. A brown PIH mark doesn't change, because the pigment sits in the skin rather than the blood.
Why the test is harder on deep skin
Almost every guide gives this test without a caveat. It deserves one: on deeper skin the blanching change is genuinely harder to see, because background melanin masks a subtle shift in redness.
There is a second complication. On Fitzpatrick V–VI, a mark can have a vascular component that simply isn't visible as red — the erythema sits beneath pigment that dominates what you see. So a mark read as pure PIH may be a mix.
The test is still worth doing — it is just most reliable on the skin tones least likely to need it, and a dermatologist has better tools where it is ambiguous.
How Deep Is The Pigment?
If you have a mark that has ignored a year of diligent effort, this is probably why — and knowing it turns a demoralising mystery into a manageable expectation.
Epidermal or dermal — the visual tells
Epidermal pigment tends to look distinctly brown or tan, with a relatively defined edge. It sits in the layer that renews itself, so it fades — slowly, but it goes.
Dermal pigment tends to look grey, slate or blue-grey, and more diffuse at the edges. It sits below the layer that turns over, which is why it is so much more stubborn.
A dermatologist can check properly with a Wood's lamp, under which epidermal pigment becomes more sharply defined while dermal pigment does not. Worth asking about if a mark has resisted everything.
Why it matters practically: deep inflammation is what drives pigment into the dermis. So the depth of a mark is largely decided while the spot is still active — which is the strongest possible argument for treating breakouts early rather than waiting them out.
Side By Side
| Feature | PIH (brown) | PIE (red) |
|---|---|---|
| Type | Pigment — melanin | Vascular — blood vessels |
| Colour | Brown, tan, grey | Red, pink, purple |
| Press test | Doesn't fade | Briefly blanches |
| More common in | Deeper tones (III–VI) | Lighter tones (I–III) |
| Typical timeline | Months to a year or more | Weeks to months |
| Worsened by | UV, picking, repeat inflammation | Irritation, harsh actives |
| Colour-correct with | Peach or orange | Green |
Marks Versus True Scars
This is the distinction that saves the most worry: PIH and PIE are flat colour changes, not scars. A true scar is a change in texture — raised, or depressed. Scars involve altered collagen and generally don't resolve alone, whereas flat marks usually fade with time and care.
The check: catch the mark in side lighting, or run a fingertip over it. Depth or elevation means textural — a scar. Smooth and level, with only colour differing, means PIH or PIE.
Skin Tone And Which You Get
If you have medium-to-deep skin, PIH is probably the mark you know best, and there is a clear reason. Deeper tones carry more reactive melanocytes, so the skin's instinctive answer to inflammation is to make pigment. It is the same machinery behind richer skin's natural resilience — it simply also means marks arrive brown rather than red.
Two habits carry outsized weight here: calming inflammation early, so less pigment is triggered in the first place, and daily sun protection, because UV deepens and prolongs pigment that already exists.
Prevention
You cannot guarantee it, but you can meaningfully shift the odds, and it reduces to one idea: less inflammation, less mark. The size and depth of what a spot leaves behind tracks how inflamed it got and how long it stayed that way.
- Treat breakouts early and gently rather than aggressively — this is the highest-leverage thing on the list.
- Don't pick or squeeze. It drives inflammation deeper, which is what pushes pigment into the dermis.
- Daily broad-spectrum sun protection — non-negotiable for pigment-prone skin.
- Support the barrier and resist over-exfoliating; harsh routines create the very inflammation that leaves marks.
- See a dermatologist sooner for persistent acne. Faster control of the acne is faster prevention of the marks.
Living With It Meanwhile
Fading takes months, and for pigment sometimes a year or more. That is a long time to be told only that patience is the answer — so here is the practical middle ground, which is free and works today.
Colour correction, in one line each
For red marks (PIE): green. Green sits opposite red on the colour wheel, so a sheer green corrector under foundation cancels the flush rather than burying it under layers of coverage.
For brown or grey marks (PIH): peach or orange. Warm tones counteract the blue-grey cast of pigment. Deeper skin generally needs a more saturated orange rather than a pale peach.
Sheer, and only where needed. A thin corrector on the mark itself, then normal coverage over the top, looks far better than heavy foundation everywhere — and there is nothing whatsoever wrong with using it while you wait.
What Sets Marks Back
Mostly well-intentioned over-effort
- Picking or popping. Drives inflammation deeper — more pigment, more redness, sometimes a scar.
- Skipping sunscreen. UV darkens pigment and stretches fading out by months.
- Over-exfoliating. Harsh scrubs and stacked acids irritate, feeding both PIE and PIH.
- Piling on actives. More is not faster; it usually means more irritation.
- Quitting too early. Fading is slow and cumulative — abandoning a gentle routine resets progress.
- Unregulated "fairness" or lightening creams. Frequently irritating and poorly controlled, and irritation deepens pigment — the precise opposite of the goal.
How Each Is Approached
Because they begin in different layers, they respond to different strategies. What follows is general skin-science education, not a treatment plan — a dermatologist is the right person to build one.
For brown marks
The pigment conversation usually centres on gentle, consistent surface renewal plus daily sun protection. Mild exfoliating acids at low, well-formulated strengths are commonly discussed for supporting natural shedding over repeated use. Niacinamide, azelaic acid and tranexamic acid all appear frequently in the literature on post-acne pigmentation.
Stronger agents — prescription tyrosinase inhibitors such as hydroquinone — belong firmly in dermatologist-supervised territory and are not something to self-source from an unregulated cream. PIH is a game of patience plus sun protection, not force.
For red marks
Because PIE is vascular, the priority is usually not irritating it further. A calm, barrier-supportive routine gives dilated vessels time to settle. Persistent or spreading redness is worth showing to a dermatologist, who can distinguish PIE from other causes of facial redness and discuss vascular options for stubborn cases.
When To See A Dermatologist
Most post-acne marks resolve with patience and gentle care. Book a review if a mark hasn't shifted over several months, is spreading or very dark, looks textural, or is causing you real distress — that last one counts, and you don't need to justify it.
A dermatologist can confirm what you're seeing, check whether pigment is epidermal or dermal, rule out look-alikes such as melasma, and discuss options from prescription topicals through to devices. Getting the diagnosis right first is what makes any approach work — and it is why a year of guessing frequently achieves less than one appointment.
Frequently Asked Questions
This article is produced by Boldpurity for educational purposes only and is not medical advice. Descriptions of melanocyte activity, epidermal and dermal pigment, capillary dilation and scar formation describe published dermatology, not the effect of any product. No Boldpurity product is presented as a treatment for post-inflammatory hyperpigmentation or erythema, and no lightening, whitening, depigmenting or fading claim is made; the referenced in-house study did not demonstrate pigmentation endpoints. Niacinamide, azelaic acid, tranexamic acid, exfoliating acids and hydroquinone are named only as general categories — prescription agents require dermatologist supervision and should never be self-sourced from unregulated products. Colour correction is a cosmetic, appearance-level suggestion only. Individual results and healing patterns vary. Persistent, spreading, changing or textural marks should be assessed by a qualified dermatologist. Aligned with the India CDSCO cosmetic framework, the Cosmetics Rules 2020 and the ASCI Code 2021.
References
- Bae-Harboe YS, Graber EM. Easy as PIE (postinflammatory erythema). Journal of Clinical and Aesthetic Dermatology. 2013;6(9):46–47.
- Davis EC, Callender VD. Postinflammatory hyperpigmentation: a review of the epidemiology, clinical features, and treatment options in skin of color. Journal of Clinical and Aesthetic Dermatology. 2010;3(7):20–31.
- Callender VD, St Surin-Lord S, Davis EC, Maclin M. Postinflammatory hyperpigmentation: etiologic and therapeutic considerations. American Journal of Clinical Dermatology. 2011;12(2):87–99.
- Maghfour J, Olayinka J, Hamzavi IH, Mohammad TF. A focused review on the pathophysiology of post-inflammatory hyperpigmentation. Pigment Cell & Melanoma Research. 2022;35(3):320–327.
- Abad-Casintahan F, Chow SKW, Goh CL, et al. Frequency and characteristics of acne-related post-inflammatory hyperpigmentation. Journal of Dermatology. 2016;43(7):826–828.
- Lawson CN, Hollinger J, Sethi S, et al. Updates in the understanding and treatments of skin and hair disorders in women of color. International Journal of Women's Dermatology. 2017;3(1 Suppl):S21–S37.
- Zawar V, Agarwal M, Vasudevan B. Treatment of postinflammatory pigmentation due to acne with Q-switched Nd:YAG laser in 78 Indian cases. Journal of Cutaneous and Aesthetic Surgery. 2015;8(4):222–226.
- Mathew ML, Karthik R, Mallikarjun M, Bhute S, Varghese A. Intense pulsed light therapy for acne-induced post-inflammatory erythema. Indian Dermatology Online Journal. 2018;9(3):159–164.
- DermNet. Post-inflammatory hyperpigmentation; post-inflammatory erythema. dermnetnz.org.
Note to editor — one link to resolve first. The Quick Answer linked "PIE (post-inflammatory erythema)" to /blogs/guides/pih-vs-pie-brown-vs-red-acne-marks-explained, while this article's own schema @id is /blogs/skin-science/pih-vs-pie. The article was linking to itself at a different URL — meaning either a duplicate of this page is live, or the link is broken. It has been removed pending your decision, and since much of the pigmentation cluster points here, this is the canonical-path question worth settling before publishing the rest. The reference list is outstanding — Bae-Harboe is correctly identified as the 2013 paper that named PIE, and the list leans properly on skin-of-colour and Indian sources; two lower-value entries were trimmed and the rest retained. Three additions, all for this brand's core audience: the blanch test's limits on deep skin, since background pigment masks the change and a mark may carry an invisible vascular component; visual tells for epidermal versus dermal pigment, because the article correctly called dermal pigment stubborn without giving any way to identify it — which leaves a reader whose mark has resisted a year of effort with no explanation; and colour correction, since fading takes months to a year and how to live with a mark meanwhile is a fair thing to answer. Tranexamic acid has been added alongside niacinamide and azelaic acid at the same generic level. The product block is scoped tightly: pigmentation endpoints were not demonstrated in SKIN-BPAG-2025-01, so it is framed strictly as barrier support that avoids adding inflammation, with the absence of a pigmentation claim stated explicitly.
