Doctor-led prevention and treatment of post-inflammatory hyperpigmentation (PIH) in Melbourne. PIH is a pigment response after acne, dermatitis, procedures or trauma — not scarring. Treatment combines topical pigment-modulators, conservative pigment-targeting laser, strict broad-spectrum SPF with iron-oxide tinting, and pre-conditioning for higher-risk Fitzpatrick III–VI skin.
- PIH is a pigment response, NOT scarring — the skin is structurally intact and pigment can fade with the right plan.
- Fitzpatrick III–VI skin types have a significantly higher PIH risk — pre-conditioning is essential before procedures.
- Topical pigment-modulators (azelaic acid, niacinamide, vitamin C, cysteamine, short-term hydroquinone) are first-line.
- Aggressive laser can worsen PIH — conservative low-fluence settings and operator expertise matter more than power.
- Daily broad-spectrum SPF 50+ with iron-oxide tinting is essential before, during and after treatment.
- Pre-condition higher-risk skin with topical pigment-modulators for 4–6 weeks before any laser, peel or microneedling.
- Control the underlying inflammation first — treating PIH while acne or eczema is still active gives disappointing results.
- Distinguish PIH from melasma, post-inflammatory erythema (PIE), drug-induced pigmentation — each needs different treatment.
- Mild PIH may fade in weeks; established or dermal pigment can take months — early intervention shortens the timeline.
- Care provided across two Melbourne clinics — Ivanhoe and Diamond Creek.
Post-Inflammatory Hyperpigmentation(PIH)
Post-inflammatory hyperpigmentation (PIH) is darkening of the skin that appears after inflammation or injury — commonly after acne, eczema, dermatitis, cosmetic procedures or minor trauma. The flat brown, tan, blue-grey or pink-brown marks can linger long after the original issue has healed. PIH is not scarring and the skin is structurally intact; with the right plan the pigment can fade. Higher-risk groups (Fitzpatrick III–VI, active inflammation, procedure aftermath) benefit from a doctor-led plan that prioritises skin stability over speed.
By Dr Christopher Irwin, MBChB, FRACGP, MMed (Skin Cancer), FACAM, MSCCA
Last reviewed 2026-06-06 · Editorial policy
Quick definition
Post-inflammatory hyperpigmentation (PIH) is darkening of the skin in areas of prior inflammation or injury — most commonly after acne, eczema, dermatitis, cosmetic procedures or minor trauma. The marks are flat, range from brown to blue-grey depending on skin tone and pigment depth, and are not scarring — the skin’s structure is intact. Treatment combines topical pigment-modulators (azelaic acid, niacinamide, vitamin C, cysteamine, short-term hydroquinone), conservative pigment-targeting laser in suitable patients, and strict daily broad-spectrum SPF with iron-oxide tinting. Fitzpatrick III–VI skin has higher PIH risk and benefits from pre-conditioning for 4–6 weeks before any procedure.
Post-inflammatory hyperpigmentation (PIH) is a very common pigment response — the skin darkens in areas that have recently been inflamed or injured. PIH is not scarring and does not cause permanent skin damage, but the flat brown, tan or grey marks can be slow to fade without the right approach.
Who is more at risk?
Medium to darker skin tones
People with Fitzpatrick skin types III–VI have more reactive melanocytes. After any inflammation — whether from acne, eczema, a procedure or trauma — these melanocytes are more likely to produce excess pigment, and the resulting PIH can be more prominent and longer-lasting.
Active inflammatory skin conditions
Acne, eczema, peri-oral dermatitis, seborrhoeic dermatitis and psoriasis can all leave PIH in their wake. Treating the underlying condition is an important first step — pigment plans started while inflammation is still active are usually disappointing.
Certain medications and supplements
Some medications sensitise the skin to pigment responses. If you are on any regular medications it is worth discussing these at your consultation before undertaking any laser or procedural treatment. See Photosensitising medications for the wider list.
People prone to pigmentation
Some individuals simply have skin that tends to over-respond to UV exposure or inflammation, even without a darker baseline skin tone. A personal or family history of melasma, freckling-tendency or post-procedure pigmentation are useful flags.
Heat- or trauma-based procedures
Chemical peels, microneedling, laser, IPL, waxing or friction can all trigger PIH if the skin is not adequately prepared or if settings are too aggressive. The most common cause of procedure-related PIH is over-treatment, not the device itself.
Can PIH be prevented?
Sun protection
Daily broad-spectrum SPF (ideally SPF 50+) before, during and after any pigment treatment is non-negotiable. UV exposure amplifies melanocyte activity and can darken existing PIH or trigger new pigment in healing skin. Iron-oxide tinted sunscreens add visible-light protection — particularly useful where pigment is already established or where melasma overlap is suspected.
Avoiding photosensitising medications
Where possible and safe, discontinuing or reducing photosensitising agents before procedures lowers PIH risk. Always discuss with your prescribing doctor first — never stop a prescription medication unilaterally. See Photosensitising medications for guidance on which agents matter most.
Pre-conditioning the skin
For higher-risk patients (particularly Fitzpatrick III–VI), we often pre-treat with topical pigment-modulators for 4–6 weeks before any procedure. This settles melanocyte activity and reduces the rebound response. Pre-conditioning is one of the highest-yield steps in skin-of-colour pigment safety.
Conservative treatment settings
The most common cause of procedure-related PIH is over-treatment. Conservative parameters, appropriate patient selection and staged treatments are safer than aggressive single sessions — particularly with energy-based devices.
Treating inflammation first
If your skin has an active inflammatory condition (acne, eczema, peri-oral dermatitis), bringing it under control before pursuing any cosmetic treatment substantially lowers PIH risk and improves the eventual cosmetic outcome.
How long does PIH last?
Mild PIH may fade within weeks. More established pigmentation — particularly where pigment sits deeper in the dermis, or in melanin-rich skin — can persist for several months or longer. Early appropriate intervention plus diligent sun protection typically leads to faster and more complete clearing.
Important: PIH that is left untreated and continues to be exposed to UV can persist for years. Time alone is not a reliable treatment.
Look-alikes — what PIH isn’t
PIH is sometimes confused with other pigmentary conditions that need different treatment. Common look-alikes include:
- Melasma — symmetric facial patches, driven by hormones and UV/visible light rather than inflammation
- Post-inflammatory erythema (PIE) — red rather than brown marks after acne or trauma, addressed with vascular-targeting rather than pigment-modulating strategies
- Solar lentigines — sun-damage-related pigment spots without preceding inflammation
- Drug-induced pigmentation — diffuse or specific patterns from medications (some chemotherapies, antimalarials, minocycline)
Correct diagnosis matters because the treatment plan diverges substantially. We confirm the pigmentary diagnosis at consultation before designing a plan.
Book a pigmentation consultation
At The Skin Doctor we combine medical diagnosis — distinguishing PIH from melasma, post-inflammatory erythema and other pigmentary disorders — with a personalised treatment plan that prioritises skin stability over speed.
You may also find these helpful:
Symptoms
- Flat brown, tan, blue-grey or pink-brown marks
- Skin darkening after inflammation or injury
- Marks that follow the site of prior acne, eczema, a procedure or trauma
- Flat marks, not raised or indented
- More prominent and longer-lasting in darker skin tones
- Colour from tan-brown in lighter skin to blue-grey or near-black in darker skin
Causes & contributors
- Inflammation or injury to the skin — acne, eczema, dermatitis or trauma
- Cosmetic, laser or energy-based procedures, especially over-treatment
- Darker skin tones (Fitzpatrick III–VI) with more reactive melanocytes
- Active, untreated inflammatory skin conditions
- Photosensitising medications and supplements
- UV exposure, which amplifies melanocyte activity
Diagnosis
PIH is diagnosed clinically. The marks are typically flat (not raised, not indented), follow the distribution of prior inflammation or injury, and range from tan and brown in lighter skin tones to blue-grey or near-black in darker skin tones. Diagnosis includes distinguishing PIH from look-alikes — melasma (symmetric facial patches driven by hormones and UV, not preceded by inflammation), post-inflammatory erythema (PIE, red rather than brown), drug- induced pigmentation, and pigmented contact dermatitis. Wood's lamp examination can help locate pigment within the epidermis versus dermis, which influences how rapidly treatment is likely to work.
Treatment options
Topical pigment-modulators (first-line)
Non-irritating actives — azelaic acid, niacinamide (vitamin B3), vitamin C, cysteamine and (short-term, specialist-guided) hydroquinone — regulate melanocyte activity and gradually fade pigmentation. Chosen by skin type, tolerance and pigmentation pattern.
Prescription-strength combinations
Medical formulations and compounded combinations (often combining a retinoid, a depigmenting agent and a mild anti-inflammatory) for persistent PIH where standard topicals have not been enough or where laser is not yet appropriate.
Chemical peels →
Gentle, medical-grade peels (e.g. mandelic, low-percentage glycolic, salicylic) can assist exfoliation and pigment reduction. Wrong peel on wrong skin can worsen PIH — selection is deliberate.
Pigment-targeting laser and LED →
Low-fluence pigment-targeting lasers and LED therapy can help established PIH in suitable patients. Aggressive parameters can trigger rebound pigmentation — expertise and conservative settings matter more than energy.
Pre-conditioning before procedures
For higher-risk patients (Fitzpatrick III–VI), 4–6 weeks of topical pigment-modulators before any procedural treatment settles melanocyte activity and reduces post-procedure rebound.
Daily broad-spectrum sun protection (essential)
SPF 50+ broad-spectrum, ideally with iron-oxide tinted coverage for visible-light protection — used before, during and after any pigment treatment. Sun protection is part of the treatment, not just prevention.
When to see a doctor
See a doctor if pigmentation appears after a cosmetic treatment or laser session, if dark marks persist after acne or dermatitis, if you belong to a higher-risk skin group (Fitzpatrick III–VI) and are planning a procedure, or if you want a personalised plan to reduce your PIH risk. Early intervention with a doctor-led plan reduces both the duration and the eventual depth of pigment, and helps distinguish PIH from look-alikes such as melasma or post- inflammatory erythema that need different treatment.
Frequently asked questions
-
Is PIH the same as scarring?
No. PIH is a pigment response — the skin's melanocytes have produced excess pigment in areas of recent inflammation or injury, but the skin is structurally intact. Scarring is a structural change in collagen (atrophic indents or hypertrophic raised tissue) and does not fade in the same way. PIH usually responds to topical pigment-modulators and sun protection. Scarring needs collagen-remodelling treatment. The two can co-exist after acne — and the treatment plan is sequenced accordingly. -
How long does PIH take to fade?
Mild PIH can fade within weeks. More established or deeper pigmentation can persist for months and sometimes longer, especially in melanin-rich skin and where pigment sits deeper in the dermis. Early appropriate intervention plus diligent daily sun protection typically leads to faster and more complete clearing — undisturbed PIH with continued UV exposure can persist for years. -
What is the difference between PIH and melasma?
PIH follows prior inflammation or injury — it appears where acne, eczema, a procedure or trauma occurred. Melasma is symmetric, usually on the cheeks, forehead and upper lip, driven by hormones (pregnancy, oral contraceptives) and UV/visible light rather than by inflammation. The two can co-exist. Distinction matters because melasma has a strong UV/visible-light driver and benefits more from iron-oxide tinted sunscreen, and from cautious laser approach — aggressive laser can flare melasma significantly. -
Will sunscreen alone fade PIH?
Sunscreen alone usually does not fade established PIH — but it is non-negotiable for stopping pigment from getting worse and for letting pigment-modulating topicals work. Daily SPF 50+ broad-spectrum, ideally tinted with iron oxides for visible-light protection, is part of the active treatment plan and not just an add-on. -
Is hydroquinone safe?
Short-term, specialist-guided hydroquinone (typically 4%) is well-established and effective for PIH and is considered safe when used appropriately. Long-term uninterrupted use is avoided because of the small risk of paradoxical darkening (exogenous ochronosis), particularly in melanin-rich skin. Cycling on and off, or using non-hydroquinone alternatives (azelaic acid, niacinamide, cysteamine), is often safer for maintenance. -
I have darker (Fitzpatrick IV–VI) skin — what should I know about PIH?
Fitzpatrick IV–VI skin has more reactive melanocytes, so PIH is more common, more prominent and longer-lasting after any inflammation or procedure. Two principles apply: control any active inflammation (acne, eczema) first, and pre-condition the skin with topical pigment-modulators for 4–6 weeks before any laser, peel, microneedling or other procedure. Conservative parameters, longer intervals between sessions and iron-oxide tinted sunscreen are also part of the safer pathway. Care is delivered through our Skin of Colour Clinic. -
Can I prevent PIH from acne breakouts?
Largely yes. The biggest driver of post-acne PIH is uncontrolled inflammation, so anything that calms acne sooner — barrier-friendly skincare, a topical retinoid (adapalene, tretinoin), azelaic acid, niacinamide, and where appropriate prescription or in-clinic treatment — reduces PIH risk. Picking and squeezing dramatically increases PIH and scarring risk. Daily SPF prevents existing marks from darkening. -
I had PIH appear after a cosmetic treatment — what should I do?
Book in for assessment rather than self-treating. PIH that appears after a cosmetic procedure has a known trigger (usually device parameters that were too aggressive for the skin type, inadequate pre-conditioning, or sun exposure too soon afterwards) and the treatment plan depends on the original modality, the pigment depth and your skin type. The earlier we start a targeted plan — pigment-modulators, strict UV protection, and conservative pigment-targeting therapy where appropriate — the better the outcome.
References
- Postinflammatory hyperpigmentation — a comprehensive overview. Treatment options and prevention. J Am Acad Dermatol. 2017.DOI: 10.1016/j.jaad.2017.01.036
- Postinflammatory hyperpigmentation — epidemiology, clinical presentation, pathogenesis and treatment. Am J Clin Dermatol. 2018.DOI: 10.1007/s40257-017-0333-6
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Medically reviewed by Dr Christopher Irwin, MBChB, FRACGP, MMed (Skin Cancer), FACAM, MSCCA · Last reviewed 2026-06-06 · Editorial policy