Decision Record
Vanity or Vice
Skincare Intelligence

Dark marks after breakouts, bites and rashes

Clinical name: post-inflammatory hyperpigmentation

Why dark marks linger after acne, bites and rashes, what helps them fade, and what can make them darker. For every skin tone.

Education, not a diagnosis. Only a clinician who examines your skin can say what you have. Every point below shows how strong the evidence is and links to its source.

Who it affects

  • Dark marks after skin inflammation can happen on any skin tone. They are reported more often on medium to deep skin, where they also tend to be darker and last longer.[1,2,3,4]Established
  • In one survey of people seeking acne care, reported in a 2010 review, dark marks were common among Black, Hispanic and Asian patients. It counted people at acne clinics, not everyone.[2,3]Thin
  • Anything that inflames or injures skin can leave a mark: acne, eczema, infections, insect bites, burns, friction, psoriasis, ingrown hairs from shaving, and procedures such as lasers, peels and freezing treatments.[1,2,3,4]Established

What it can look like

  • A flat mark sits where the skin was inflamed or hurt, such as the site of a spot, bite or patch of rash.[2,4]Established
  • When the pigment stays in the upper skin (epidermal), the mark tends to look brown. When pigment drops into the deeper skin (dermal), it can look grey or blue-grey and fades more slowly.[1,3]Supported
  • Sunlight can make marks darker, and new inflammation in the same place keeps them going.[2,4]Supported

What helps

Calm the cause first

Marks keep forming for as long as whatever is causing them keeps going.

  • The first step is getting the cause under control, such as acne or eczema, and ideally early.[2,3,5]Mechanistic only
  • Dermatologists often treat acne and its dark marks at the same time, rather than waiting for the breakouts to finish.[5]Mechanistic only
  • Acne treatments can be introduced gently. The American Academy of Dermatology suggests starting benzoyl peroxide at a lower strength to limit irritation.[5]Mechanistic only

Protect your skin from light every day

  • In a systematic review, daily broad-spectrum sunscreen was the most consistent way to prevent marks. Most people studied had light-to-medium brown skin and marks after laser treatment, so it tells us less about deeper skin and acne marks.[6]Supported
  • For dark spots on darker skin, the American Academy of Dermatology suggests a tinted, broad-spectrum sunscreen of SPF 30 or higher that contains iron oxide.[7]Mechanistic only
  • Tinted formulas add protection from visible light, which standard UV filters do not block.[8,9]Supported

Be gentle with your skin

  • Skip scrubbing, picking and squeezing. Each one adds injury, and injury can leave a new mark.[2,5]Mechanistic only
  • Irritation from a skin-care active can itself create or darken marks. That includes retinoids, acids, peels and lasers, the same things used to fade marks.[1,3,10,11]Supported
  • Adding one new active at a time, and avoiding irritating products, keeps that risk lower and makes it easier to tell what your skin is reacting to.[3,7]Mechanistic only

Ingredients with some evidence

These are ingredients the sources discuss, not a shopping list. Some need a prescription, depending on where you live.

  • Retinoids (such as tretinoin) have trial support. In a 40-week trial in Black patients, tretinoin faded marks more than a plain cream, but irritated skin was common among the people using it.[10,11]Supported
  • Azelaic acid reduced dark marks more than a plain cream in trials that included deeper skin tones and acne marks. Mild stinging was more common. One of those trials was in a single country.[12,13,14]Supported
  • Hydroquinone is a long-standing option, used in time-limited courses with a clinician. It is not legally sold over the counter in the US. One review of studies in skin of color found it did less well than retinoids, so where it ranks is debated.[2,11,15,16]Mixed
  • Niacinamide and vitamin C have smaller, shorter studies behind them. Kojic acid is widely listed, and skin reactions to it are reported as common.[3,17,18]Thin
  • Clinical references describe combining steps (calming the cause, sun protection and a topical) as working better than any one of them alone.[2]Mechanistic only

Give it time

  • Marks in the upper skin usually fade over about 6 to 12 months once the cause has stopped.[2,7]Supported
  • Deeper marks can take years and may not fully fade.[2,4,7]Supported

What to avoid

  • Picking, squeezing or scrubbing spots and marks.[2,5]Mechanistic only
  • Stacking several strong actives at once. More irritation means more chance of new marks.[1,3,7]Supported
  • Liquid bleach, and imported creams that may contain unlisted steroids or mercury.[7,19]Mechanistic only
  • Rushing into peels or lasers. The American Academy of Dermatology advises seeing a dermatologist first, because these can cause lasting color change on darker skin.[1,5]Mechanistic only
  • Using hydroquinone for long stretches without a clinician. Long use has been linked to ochronosis, a blue-black darkening that may be permanent.[15,16,20]Supported

When to see a clinician

  • New marks keep appearing because acne, eczema or another cause is not under control.[2,5]Mechanistic only
  • Marks look grey or blue-grey, or have not changed after many months of sun protection and gentle care.[1,2]Supported
  • You are considering a peel, a laser or a prescription treatment.[5]Mechanistic only
  • A single dark spot is new, changing or irregular, including on a palm, sole, nail or lip. That needs a prompt check, not a fading plan.[21,22]Mechanistic only
  • Blue-black or grey darkening appears where a lightening cream was used.[15,20]Thin

Label claims to question

“Brightening”
Usually a cosmetic claim about radiance or evenness, and not a regulated term. It does not show a product fades dark marks, or at what strength. FDA has found some illegal mercury or hydroquinone products sold as brightening, so the word tells you nothing about safety either way.[17,18,23]
“Dark spot corrector”
Implies it targets marks. It does not show how well or how fast it works, or that it won't irritate, and irritation can cause new marks. A US over-the-counter hydroquinone corrector is not legally marketed.[1,3,16]
“Hydroquinone-free”
Tells you hydroquinone is not in it. It does not show the product works as well or irritates less. A few alternatives have trial data; many do not.[11,24,25]
“Clinically proven to fade dark spots”
May point to a trial, but without its size, length, skin types and comparison it cannot tell you it works on deeper skin or for the long term. Many pigment trials are small and short.[26,27,28]

Where the evidence is thin

  • The best prevention evidence comes mostly from people with light-to-medium brown skin and marks after lasers. How well it applies to the deepest skin tones, or to marks after acne or eczema, is uncertain.
  • Where hydroquinone ranks for dark marks is disputed. Clinical references call it a mainstay, while one review of mostly uncontrolled studies found it did less well than retinoids.
  • Adapalene, tazarotene, mandelic acid and kojic acid lack verified trials specific to dark marks in the sources reviewed. Niacinamide and vitamin C studies are small and short.
  • Tranexamic acid and cysteamine have some melasma data, but evidence for dark marks after inflammation is thin.
  • Waxing and threading are plausible causes of marks, since they irritate skin, but the sources reviewed did not name them.
  • Some of the reference material is old: one key patient page dates from 2015 and a major review from 2010.

Keep going

Sources

Retrieved and read for this guide; reviewed 2026-09-13. A source listed here says what it establishes and what it does not — a citation is not an endorsement.

  1. [1]Postinflammatory hyperpigmentation · DermNet (NZ), 2015Establishes: PIH is more intense and longer-lasting in darker skin. Inflammation drives melanin production, with an epidermal form and a dermal (macrophage) form. Physical treatments can worsen PIH by injuring the epidermis.Does not establish: Any trial data or comparative efficacy — it gives none. The page was last updated in December 2015.
  2. [2]Postinflammatory Hyperpigmentation (StatPearls) · NCBI Bookshelf (Lawrence, Syed, Al Aboud), 2024Establishes: PIH is more common in Fitzpatrick IV–VI; up to 65% in darker-skinned acne patients. Triggers include acne, dermatitis, infections, lasers, peels, cryotherapy and burns. Epidermal PIH resolves in about 6–12 months; dermal PIH is slow and may be permanent. Prevention: sunscreen, gentle care, not picking, treating inflammation early. Combination therapy is described as most effective.Does not establish: Systematic grading — it is not a systematic review. Does not discuss niacinamide or tranexamic acid.
  3. [3]Postinflammatory hyperpigmentation: a review of the epidemiology, clinical features, and treatment options in skin of color · J Clin Aesthet Dermatol 3(7):20–31, 2010Establishes: PIH is more frequent and more severe in darker skin. Cites a 2002 acne study reporting PIH in 65.3% of African-American, 52.7% of Hispanic and 47.4% of Asian acne patients. Explains epidermal vs dermal PIH. First-line care is treating the underlying inflammation plus photoprotection and depigmenting agents; treatment irritation can worsen PIH. Agents covered: hydroquinone 2–4% (ochronosis risk with prolonged use), azelaic acid 20%, retinoids (irritation in up to about 50%), niacinamide, kojic acid (contact dermatitis common), vitamin C. Glycolic and salicylic peels need care. Longer laser wavelengths are described as lower-risk.Does not establish: Graded evidence — it is a narrative review, 16 years old. The survey figures are secondary citations; the primary study was not fetched.
  4. [4]Post-Inflammatory Hyperpigmentation (PIH) · Skin of Color Society, 2026Establishes: PIH follows inflammation or irritation (acne, burns, eczema, allergies, infections, bug bites, psoriasis and others). It is very common in darker skin (over 65% of African Americans is cited). It can take months to years to fade, sunlight darkens it, aggressive procedures can worsen it, and dermal PIH is hard to treat.Does not establish: The 65% figure — it has no citation on the page, and appears to match an acne-cohort survey (see davis-callender-2010).
  5. [5]10 tips for clearing acne in darker skin tones · American Academy of Dermatology, 2026Establishes: Advises treating acne and dark spots together and early, to lower the chance of keloids and dark spots, and starting benzoyl peroxide at a low strength (2.5%) to limit irritation. Suggests swapping oil-based hair products for water- or glycerin-based ones if acne is on the forehead or temples ('pomade acne'), and using non-comedogenic products and gentle care. Says to avoid scrubbing and picking, and to see a dermatologist before peels, microdermabrasion or lasers, which can leave lasting light or dark spots in darker skin without expertise.Does not establish: How often these complications happen, or trial evidence for the tips. It does not address isotretinoin.
  6. [6]Prevention of Post-Inflammatory Hyperpigmentation in Skin of Colour: A Systematic Review · Australas J Dermatol 66(3), 2025 · read at abstract levelEstablishes: Across 14 studies and 369 patients (mostly Asian, types III–IV, mostly laser-induced PIH), sunscreen alone or combined was the most consistently successful prevention. Topical steroids and systemic tranexamic acid were of limited effect, and cooling devices worsened PIH.Does not establish: Much about types V–VI (few participants), or PIH from acne or eczema rather than procedures.
  7. [7]How to fade dark spots in darker skin tones · American Academy of Dermatology, 2025Establishes: Advises tinted broad-spectrum SPF30+ sunscreen with iron oxide and treating the underlying cause. Lists azelaic, glycolic and kojic acids, retinoids and vitamin C as ingredients. Says to avoid irritating products, liquid bleach, and imported products with unlisted steroids or mercury. Fading takes 6–12 months for lighter spots and can take years for deeper ones.Does not establish: Any ranking of the ingredients, or trial evidence for them. Not individual advice.
  8. [8]Visible light. Part II: Photoprotection against visible and ultraviolet light · J Am Acad Dermatol, 2021 · read at abstract levelEstablishes: Organic and inorganic UV filters do not protect against visible light; tinted sunscreens do. Regulation of visible-light protection differs by region.Does not establish: A standard for testing or labelling visible-light protection — it does not define one, so it cannot say how much a given tinted product blocks.
  9. [9]Sunscreen Selection · Skin of Color Society, 2026Establishes: Mineral filters may leave a white cast on darker skin. Options: tinted shades, thin layers, micronised mineral formulas, or foundation layered on top. Tinted sunscreens with iron oxides protect against visible light and are especially useful for melasma and hyperpigmentation. Use about ½ teaspoon for face and neck and reapply every 2 hours.Does not establish: Any product comparison or white-cast testing.
  10. [10]Topical tretinoin therapy for hyperpigmented lesions caused by inflammation of the skin in black patients · N Engl J Med, 1993 · read at abstract levelEstablishes: Over 40 weeks in 54 completers, tretinoin 0.1% lightened PIH lesions about 40% vs 18% with vehicle. Retinoid dermatitis occurred in 12 of 24 tretinoin users.Does not establish: The best concentration — a single, older, small trial at high strength.
  11. [11]Treatment of Post-Inflammatory Hyperpigmentation in Skin of Colour: A Systematic Review · J Cutan Med Surg 28(5), 2024 · read at abstract levelEstablishes: Across 48 studies and 1,356 people (70% Black), partial improvement was seen in 85% on topical retinoids and 66% on lasers. Laser monotherapy sometimes worsened PIH. Chemical peels and hydroquinone showed lower efficacy in this dataset.Does not establish: A ranking — the studies are heterogeneous and mostly uncontrolled.
  12. [12]Azelaic acid 20% cream in the treatment of facial hyperpigmentation in darker-skinned patients · Clin Ther, 1998 · read at abstract levelEstablishes: In 68 patients with types IV–VI over 24 weeks, azelaic acid 20% gave greater pigment reduction than vehicle. Mild burning or stinging was more frequent.Does not establish: Results for any one kind of hyperpigmentation — types were mixed. Older trial.
  13. [13]Effects of 15% Azelaic Acid Gel in the Management of Post-Inflammatory Erythema and PIH in Acne Vulgaris · Dermatol Ther (Heidelb), 2024 · read at abstract levelEstablishes: RCT, 72 enrolled and 60 completing: azelaic acid 15% gel reduced the post-acne hyperpigmentation index and melanin vs placebo at 12 weeks, with minimal adverse reactions.Does not establish: Results across phototypes — a single-country cohort (China), phototype mix not captured.
  14. [14]Efficacy and safety of azelaic acid gel 15% in PIH and acne: 16-week baseline-controlled study · J Drugs Dermatol, 2011 · read at abstract levelEstablishes: Uncontrolled pilot supporting azelaic acid 15% for both acne and PIH in darker skin types.Does not establish: A controlled comparison — no control group, pilot size.
  15. [15]Hydroquinone (bleaching cream) · DermNet (NZ), 2021Establishes: Hydroquinone inhibits tyrosinase and acts on epidermal (not dermal) pigment. The typical course described is twice daily for about 3 months, stopped if there is no improvement, then twice-weekly maintenance. Risks include irritant dermatitis (more likely above 4%) and exogenous ochronosis with prolonged high-concentration use. It is prescription-only in NZ and many countries.Does not establish: A universal maximum duration — it sets none. Legal status outside NZ is not detailed.
  16. [16]FDA works to protect consumers from potentially harmful OTC skin lightening products · US Food and Drug Administration (Drug Safety Communication), 2022Establishes: Under the CARES Act, over-the-counter skin lighteners containing hydroquinone needed FDA approval to be legally marketed from 23 September 2020, and there are no approved OTC skin lighteners. Reported harms include rash, facial swelling and exogenous ochronosis, which may be permanent. At the date of the notice (April 2022) the only FDA-approved hydroquinone product was a prescription triple-combination cream for melasma.Does not establish: That hydroquinone does not work — the finding is regulatory, not about efficacy. It says nothing about prescription products after April 2022, or about any market outside the US: the EU cosmetics ban this entry used to mention is not on this page.
  17. [17]The effect of niacinamide on reducing cutaneous pigmentation and suppression of melanosome transfer · Br J Dermatol, 2002 · read at abstract levelEstablishes: Lab work plus small clinical trials. Niacinamide inhibited melanosome transfer (35–68% in coculture) without inhibiting tyrosinase, and reduced hyperpigmentation versus vehicle after 4 weeks in small trials.Does not establish: Results in PIH-specific or skin-of-colour-specific cohorts — the trials were short and small. Company-affiliated research (not assessed further).
  18. [18]Efficacy of topical vitamin C in melasma and photoaging: A systematic review · J Cosmet Dermatol, 2023 · read at abstract levelEstablishes: Across 7 studies and 139 volunteers, topical vitamin C showed lightening, and long-term use may be needed.Does not establish: An optimal concentration, or PIH-specific results. Very small evidence base.
  19. [19]Mercury Poisoning Linked to Skin Products · US Food and Drug Administration, Consumer Updates, 2022Establishes: Mercury is illegally added to some skin lighteners and anti-ageing creams. Label terms to watch: mercurous chloride, calomel, mercuric, mercurio, mercury. These products are often sold in shops serving Latino, Asian, African and Middle Eastern communities, and online. Health effects are listed, and if exposed FDA's steps are to stop use, wash, contact poison control, and seal the product.Does not establish: That every unlabelled product contains mercury, or how common exposure is.
  20. [20]Exogenous Ochronosis: Characterizing a Rare Disorder in Skin of Color · J Clin Med 12(13):4341, 2023 · read at abstract levelEstablishes: Retrospective case series with review. In 25 patients with exogenous ochronosis, the average lightening-cream use was 9.2 years. The blue-black pigment appeared mostly on the cheeks, forehead and temples. The condition mainly affects people with skin of colour and is distressing.Does not establish: Risk per user, or any duration or concentration that carries no risk — a case series cannot identify either.
  21. [21]Finding skin cancer in darker skin tones · American Academy of Dermatology, 2025Establishes: People with darker skin need sun protection too. Skin cancer in darker skin is often advanced by the time it is diagnosed. Advises tinted iron-oxide SPF30+ broad-spectrum water-resistant sunscreen.Does not establish: Prevalence figures for pigmentation.
  22. [22]Approaches to the evaluation of lip hyperpigmentation · Int J Dermatol, 2012 · read at abstract levelEstablishes: Lip darkening has physiologic or genetic, inflammatory, endocrine, drug-related and neoplastic causes. The evidence is largely case reports and small series.Does not establish: Prevalence by skin tone, or treatment efficacy.
  23. [23]FDA Warns Consumers of Skin Products Containing Mercury and/or Hydroquinone · US Food and Drug Administration (Health Fraud), 2026Establishes: FDA testing since 2019 found some lighteners with mercury at 47 to 27,762 ppm and/or hydroquinone. The products were marketed as whitening, bleaching or brightening, came from several countries, and were sold on large online marketplaces. Kidney, nerve and skin harms are listed. Repeats that there are no legal OTC lighteners in the US.Does not establish: Steroid adulteration, which it does not cover. It does not show that every product using the word 'brightening' contains these ingredients.
  24. [24]Efficacy and safety of cysteamine 5% cream for melasma: systematic review and meta-analysis of RCTs · Arch Dermatol Res, 2024 · read at abstract levelEstablishes: 7 randomised trials: cysteamine beat placebo, with no significant difference from hydroquinone 4%. Irritation rates were similar to hydroquinone and higher than placebo.Does not establish: That cysteamine and hydroquinone are equivalent — few, small trials cannot show that.
  25. [25]A Double-Blind, Randomized Clinical Trial of Niacinamide 4% versus Hydroquinone 4% in the Treatment of Melasma · Dermatol Res Pract, 2011 · read at abstract levelEstablishes: Split-face RCT in 27 patients over 8 weeks: both sides improved with no colorimetric difference. Good-to-excellent response was 44% with niacinamide vs 55% with hydroquinone. Side effects were 18% vs 29%.Does not establish: Equivalence — too small and too short to show it.
  26. [26]Systematic review of randomized controlled trials on interventions for melasma: an abridged Cochrane review · J Am Acad Dermatol, 2014 · read at abstract levelEstablishes: 20 randomised trials, 2,125 participants: triple-combination cream beat hydroquinone alone (RR 1.58), azelaic acid 20% beat hydroquinone 2% (RR 1.25), and tretinoin beat placebo.Does not establish: Long-term outcomes or relapse. Methodology was poor and the studies were short.
  27. [27]Melasma Treatment: An Evidence-Based Review · Am J Clin Dermatol, 2020 · read at abstract levelEstablishes: Across 113 controlled trials and 6,897 participants: triple combination cream and hydroquinone were the most effective. Oral tranexamic acid is promising for moderate or severe recurrent melasma. Peels and lasers showed mixed or inferior results with more adverse events.Does not establish: Long-term results — studies were small with short follow-up.
  28. [28]Self-applied topical interventions for melasma: systematic review and meta-analysis · Br J Dermatol, 2022 · read at abstract levelEstablishes: Across 36 investigator-blinded RCTs, triple combination cream, hydroquinone and tretinoin were effective. Sunscreen covering both visible and UV light improved hydroquinone's effect. Tranexamic acid and cysteamine comparisons were meta-analysed.Does not establish: A definitive ranking. Certainty ranged from very low to high.
Near-black ground, following the device