Melasma vs. Post-Inflammatory Hyperpigmentation: Know the Difference

What Is Melasma?

Melasma is a chronic pigmentation disorder caused by an overproduction of melanin in response to hormonal fluctuations and ultraviolet light exposure. It most commonly presents as symmetrical, blotchy patches on the cheeks, forehead, upper lip, and chin. The word "melasma" derives from the Greek for black spot — and while it affects all skin tones, it is disproportionately prevalent in individuals with Fitzpatrick types III through VI.

The primary triggers for melasma are estrogen and progesterone, which is why the condition is often referred to as the "mask of pregnancy." Oral contraceptives, hormone replacement therapy, and sun exposure can all initiate or worsen it. Crucially, melasma is a recurring condition. Even when successfully faded, it can return with sun exposure or hormonal shifts. This chronicity is one of the defining features that separates it from other forms of hyperpigmentation.

What Is Post-Inflammatory Hyperpigmentation?

Post-inflammatory hyperpigmentation (PIH) is the skin's response to injury or inflammation. When the skin experiences trauma — whether from acne, eczema, a cut, an aggressive treatment, or even an insect bite — melanocytes release excess pigment as part of the healing response. That pigment then deposits in the epidermis or dermis, leaving behind a dark mark that can persist long after the original wound has resolved.

PIH is not a disease. It is a wound-healing byproduct. This distinction matters enormously for treatment. Unlike melasma, PIH has no hormonal component and is not chronically driven by UV exposure in the same way. Its intensity correlates directly with the severity and depth of the original inflammation. Individuals with melanin-rich skin — particularly Fitzpatrick types IV, V, and VI — are more prone to developing PIH because their melanocytes are inherently more reactive and produce more pigment in response to insult.

Why They Look the Same — But Aren't

Both melasma and PIH produce brown, tan, or gray-brown discoloration on the skin. Both can appear on the face. Both worsen with sun exposure. These overlapping characteristics lead patients and, unfortunately, some providers to group them together under the broad label "hyperpigmentation" and treat them interchangeably. That is a clinical error.

The key differences lie in their triggers, distribution patterns, and behavior over time. Melasma tends to be bilateral and symmetric, following hormone-driven pathways. PIH tends to be localized, appearing precisely where inflammation occurred. Melasma persists and cycles; PIH fades on its own — often significantly — if the inflammation source is eliminated and the skin is protected from further insult.

Misidentifying PIH as melasma can lead to aggressive protocols that exacerbate the problem. And misidentifying melasma as PIH leads to treatments that temporarily improve appearance without addressing the chronic hormonal driver — setting the patient up for repeated disappointment.

The Role of Fitzpatrick Type

Fitzpatrick skin typing is not just a classification system — it is a clinical decision-making framework. Melanin-rich skin types (IV–VI) carry a significantly higher risk of post-inflammatory darkening from any skin intervention, including treatments intended to improve pigmentation. A laser setting appropriate for a Fitzpatrick II patient can cause severe PIH in a Fitzpatrick V patient. This is why understanding which type of hyperpigmentation you are treating — and in which skin type — is foundational to safe care.

Treatment Hierarchy: Melasma

Because melasma is hormonally driven and UV-sensitive, treatment must begin with suppression of its triggers. Broad-spectrum SPF 50+ daily — without exception — is the single most important step. Without it, no other treatment will hold.

Topical protocols for melasma typically center on melanin-inhibiting ingredients: tranexamic acid, kojic acid, azelaic acid, niacinamide, and (under clinical supervision) hydroquinone. These work by interrupting the melanin synthesis pathway at various points. Results are gradual — expect 8 to 12 weeks of consistent use before meaningful fading.

Treatment Hierarchy: Post-Inflammatory Hyperpigmentation

The first step in treating PIH is removing the source of inflammation. If acne is producing the marks, the acne must be controlled before pigmentation can be addressed. Treating the brown marks while the underlying inflammation persists is an exercise in futility.

Once inflammation is controlled, the same melanin-inhibiting agents used for melasma can accelerate PIH fading. Retinoids promote cellular turnover, helping surface-level pigment shed more quickly. Chemical exfoliants (AHAs such as glycolic and lactic acid) support the same process. For deeper, dermal PIH in patients with stable skin, carefully selected energy-based treatments may be appropriate — but only after thorough skin prep and with Fitzpatrick-appropriate parameters.

The good news about PIH: it fades. With consistent sun protection and appropriate topical care, most epidermal PIH will resolve within 6 to 12 months. Dermal PIH takes longer but follows the same trajectory. Patience and protection are the two pillars.

The PSRx Approach to Hyperpigmentation

At PSRx Body & Skin — a Clinical Skin Intelligence Platform serving clients in Chicago and Greensboro, NC — every pigmentation case begins with a thorough intake that includes Fitzpatrick typing, trigger identification, and a review of prior treatments. We do not assume. Misclassification is how pigmentation gets worse, not better.

Our practitioners build protocols around the specific type and depth of pigmentation present, the patient's skin type, and their hormonal and lifestyle context. For melasma, we prioritize topical suppression and photoprotection as the foundation, layering in clinic treatments only when the condition is appropriately managed. For PIH, we focus first on resolving active inflammation, then deploying targeted treatment to accelerate fading.

If you have visible hyperpigmentation and are unsure which type you are dealing with, starting with a skin assessment is the right first step. A clinical intake that maps your Fitzpatrick type, skin history, and active concerns gives your provider the information they need to build a protocol that actually works. You can also explore our skin concerns library for a deeper look at how we approach pigmentation, acne, and other conditions clinically.

More Articles