Post-Inflammatory Hyperpigmentation on Darker Skin Tones

Patients usually call it a dark spot, a scar, a shadow left behind after a breakout. StatPearls, in an update from November 2024, establishes this as the core mechanism. It's a pigment problem, not scar tissue or permanent structural damage, triggered by something else entirely, whether that something is acne, a rash, a burn, or a procedure gone sideways.

Where that pigment settles changes everything about how it looks and how hard it is to treat.

The triggers themselves are familiar to anyone who treats skin of color: acne vulgaris, atopic dermatitis, and impetigo top the list, according to StatPearls. The melanin it left behind is not.

Why darker skin produces more PIH

Darker skin doesn't just show PIH more visibly. The 2025 University of British Columbia systematic review, published in the Australasian Journal of Dermatology, points to this as the structural reason more melanosomes get transferred into the epidermis after any inflammatory event.

That's only half the story. The inflammatory cascade that triggers melanin production runs stronger and lasts longer. Markiewicz and colleagues, writing in 2022, tied these enhanced inflammatory responses not just to melanogenesis but to a broader pattern of injury-related skin pathology. The same injury that might leave faint, short-lived discoloration on lighter skin can trigger a more intense and more stubborn pigment response in darker skin, because the cells involved are wired to respond more aggressively at every step.

The scale of this is reflected in who shows up in dermatology clinics for it. StatPearls notes that PIH is especially prevalent in people of African, Asian, and Latin American descent, where it ranks among the most common reasons for a dermatology visit. The biology demands a different level of care.

The role of visible light (and why standard sunscreen is not enough)

A patient wearing sunscreen every day and still watching their PIH darken is not imagining it or doing something wrong. High-energy visible light, or HEVL, works through a separate pathway that most sunscreens never touch.

A 2026 review indexed on PubMed lays out the mechanism: HEVL activates a receptor called opsin-3 on melanocytes, which upregulates a protein called MITF and leads to the formation of melanosomes that resist being broken down by the skin's normal recycling process (autophagy).

That raises an important question: if visible light is doing this much damage, why does it get so little attention in most skincare advice? So a patient diligently applying a high-SPF sunscreen that ignores visible light is still getting hit by the exact trigger driving their pigmentation, every day, indoors included. For Fitzpatrick III through VI skin, that gap in protection helps explain a pattern clinicians see often: PIH that refuses to fade, or even worsens, despite what looks on paper like responsible sun protection.

What the evidence says about preventing PIH

Sunscreen is the one strategy with evidence behind it that holds up consistently across studies in skin of color for preventing PIH. Cooling air devices, somewhat counterintuitively, actually made PIH worse in some cases.

But not every sunscreen formula addresses the mechanism described above. A 2025 randomized trial in Dermatology and Therapy tested a sunscreen formulated with sclareolide and niacinamide and found measurable improvement in colorimetric indices and erythema compared to unprotected skin, adding further support to the idea that formulation details, not just SPF number, determine how well a sunscreen performs for this population.

Consistency carries as much weight as the formula. Applying sunscreen most days, or only when heading outdoors, isn't the same as applying it daily, because both UV and visible-light exposure accumulate over time regardless of whether the sun is the direct source. This also reframes where prevention sits relative to treatment. Preventing new pigment from forming is a faster, more reliable win than trying to clear pigment that's already deposited. That logic extends to procedures, too. The UBC review found a meaningful rate of PIH among skin of color patients undergoing laser treatments and chemical peels, which makes sunscreen before and after any procedure a required step in the protocol, not an optional add-on at the end of a visit.

The topical treatment ingredients with the strongest evidence (what each one does and for whom)

No single cream or serum clears PIH on its own, and claims that one ingredient does it all should raise an eyebrow.

Hydroquinone, typically used at 2 to 5 percent, remains the most studied depigmenting agent available. The UBC review found that systemic tranexamic acid showed inconsistent results for prevention, though topical TXA plays a different role once PIH is already present and being actively treated.

Azelaic acid, used at 15 to 20 percent, inhibits tyrosinase while selectively targeting overactive melanocytes.

Vitamin C, in the form of L-ascorbic acid or a stabilized derivative, adds antioxidant protection against oxidative-stress-driven pigmentation while also inhibiting tyrosinase. Retinoids, including tretinoin and adapalene, speed up epidermal cell turnover, helping pigment-laden cells shed faster than they otherwise would. They're effective, but they carry a real irritation risk in Fitzpatrick III through VI skin, and that irritation itself can trigger fresh PIH. Retinoids need to be introduced at a low dose and increased slowly.

Bakuchiol offers an alternative path for patients who react poorly to retinoids.

How to sequence treatments without making PIH worse

Choosing the right ingredients solves only part of the problem. Because the treatment itself can cause the very inflammation that produces new PIH, sequencing deserves as much attention as ingredient selection.

A stepwise approach starts with building a tolerant baseline before adding anything aggressive. For acne-related PIH, the combination protocol with the strongest evidence looks something like this: niacinamide or azelaic acid as the well-tolerated, anti-inflammatory baseline; a vitamin C serum in the morning layered under tinted SPF for antioxidant and visible-light defense; and a low-dose retinoid or bakuchiol introduced gradually in the evening, not applied nightly from day one.

Why does order matter this much? Patience matters just as much as sequencing. Patients who don't expect that timeline often escalate their routine out of frustration, adding stronger actives faster than their skin can tolerate, which only restarts the cycle.

StatPearls identifies combination therapy as the most effective overall treatment approach, but combination here means layered and paced, not simultaneous and aggressive.

When lasers are and aren't appropriate for darker skin tones

Procedures sit in a strange position for PIH in darker skin: the same treatments that clear pigment reliably in lighter skin can cause new pigment in Fitzpatrick IV through VI patients if the wrong settings are used.

Picosecond lasers carry a relative contraindication in Fitzpatrick IV through VI skin. Asian, Hispanic, and African American patients face an increased risk of developing PIH from the procedure itself, not from the condition the laser was meant to treat. Longer wavelengths, particularly the 1064 nm Nd:YAG laser, are generally considered a safer choice for darker skin. They require lower energy input, penetrate deeper to reach dermal melanin, and spare the epidermis more effectively than shorter wavelengths do.

Dermal PIH presents a genuine dilemma here. Since topical agents aren't proven effective against dermal hypermelanosis, laser treatment sometimes becomes the only real option, and that's precisely the scenario where wavelength choice and operator skill carry the most weight. Whether to pursue a laser procedure at all, and which system to use, should involve a dermatologist with documented, specific experience treating skin of color, rather than a general aesthetician or laser technician working from a standard protocol built for lighter skin.

Where research on PIH in skin of color still falls short

The guidance above rests on real evidence, but that evidence has limits.

The composition of the studies themselves illustrates the gap. For Fitzpatrick V and VI skin specifically, direct evidence is thin. Many of the clinical recommendations applied to those patients are extrapolated from studies that never actually included them. That's a real limitation, not a reason to dismiss the guidance, but a reason to treat it as a starting point that a clinician should adjust based on individual response.

Cost compounds the problem. None of this reflects a failure on the patient's part to find the right serum. It reflects a research and access system that has underinvested in a condition that disproportionately affects populations already underserved in dermatology, and a clinician can adjust for what the studies don't cover in a way a product label alone cannot.

How hormonal contraceptives interact with PIH risk (what patients with darker skin should know)

Contraceptive choice tends to live in a separate conversation from skincare, but for patients prone to PIH, the two are connected in ways patients should understand before, not after, a method switch. Hormonal contraceptives containing synthetic estrogen can activate melanocytes directly, producing melasma, a condition that shares much of its underlying mechanism with PIH and shows the same pattern of being worse in darker phototypes and in anyone with a prior history of pigmentation issues.

That risk isn't evenly distributed. But the picture isn't one-directional. Progestin-only methods can worsen acne in some patients, which creates a real trade-off: the method that avoids stimulating melanocytes directly might, for some patients, increase the acne burden that drives PIH through an entirely different pathway.

That tension matters most for patients carrying both a history of PIH and a history of acne, where a contraceptive decision ends up touching two separate pigmentation risks at once. None of this argues for or against any particular method. It argues for making sure skin history, not just reproductive history, is part of the conversation with a provider when choosing a contraceptive.

What telehealth and AI can do for PIH in darker skin

Telehealth has opened real access to dermatological care for patients who might otherwise wait months for an in-person appointment or have no dermatologist nearby at all. For many PIH cases, telehealth is a meaningful expansion of access.

AI-assisted diagnostic tools are a different matter, and the gap here is documented. A 2025 systematic review found that AI diagnostic tools in dermatology perform meaningfully worse on darker skin tones than on lighter ones. A HCPLive podcast featuring leaders from the Skin of Color Society explained the mechanism behind that gap: these systems learn from training data, and historical dermatology datasets underrepresent darker skin, so the algorithm's blind spot reflects the same research gap described earlier. Researcher Roxana Daneshjou's work, discussed in that same episode, found that skin cancer detection algorithms performed significantly worse at identifying malignancies on darker skin, which carries a direct warning for pigmentation triage tools too: misclassifying PIH could delay catching something more serious.

Access gaps persist even within telehealth itself. A 2026 retrospective study of the VA's asynchronous platform, My VA Images, found that patients invited to use the platform skewed White, urban, and already better connected to dermatology care. The patients who stood to benefit most from telehealth expansion were the least likely to be offered it in practice. The case here is for pairing AI's efficiency with mandatory human oversight, not for abandoning the tools altogether.

How to get useful clinical help for PIH

Getting real traction on PIH starts with finding a provider who has actual experience treating Fitzpatrick III through VI skin. That matters because, as the earlier sections make clear, the same treatment protocol that works safely on lighter skin can trigger new PIH on darker skin. Asking a provider directly about their experience treating patients with skin of color is a fair and useful question, not an awkward one.

Walking into a consultation, whether virtual or in person, with the right information makes the assessment far more productive.

A productive first assessment won't hand over an instant fix. What it should establish is whether the pigmentation is epidermal or dermal, what likely triggered it, and a treatment sequence matched to both skin type and pigment depth. Asynchronous telehealth is a legitimate, clinically sound starting point for the large majority of PIH cases. A message-based consultation with a real, licensed clinician offers something no product marketing, social media recommendation, or AI-generated assessment can: a trained eye that can judge pigment depth, recommend the right tier of treatment, and recognize when an in-person visit is actually necessary.

That access carries real financial weight too. Prescription options like topical tretinoin, prescription-strength hydroquinone, and higher-concentration azelaic acid are often unavailable over