Post-Inflammatory Hyperpigmentation (PIH)

Why Dark Spots Happen and How to Fade Them in Skin of Color

Key Takeaways

• Post-inflammatory hyperpigmentation (PIH) is the darkening that can happen after the skin becomes inflamed or irritated. It is not a scar and not a disease on its own—it is the skin’s pigment response to inflammation.

• PIH is especially common in skin of color. Acne, eczema, razor bumps, bug bites, burns, and even harsh skincare products can all leave dark marks behind.

• In deeper skin tones, PIH often lasts longer and looks more noticeable because melanocytes are more reactive and produce more pigment in response to inflammation.

• The most important treatment step is controlling the condition causing the inflammation. If acne, eczema, or razor bumps are still active, new dark spots will keep forming.

• Daily sunscreen matters—even for darker skin. UV light and visible light can both worsen PIH, which is why tinted sunscreen with iron oxide is especially helpful for many people with skin of color.

• PIH can improve, but it takes time. Surface-level PIH may fade over months. Deeper pigment can last much longer.

What Is Post-Inflammatory Hyperpigmentation?

Post-inflammatory hyperpigmentation—usually shortened to PIH—is one of the most common reasons people with skin of color feel like their skin “healed, but never really went back to normal.” It happens when the skin becomes inflamed or injured and responds by making extra melanin, the pigment that gives skin its color. Once that inflammation settles, what can remain is a flat dark spot or patch that lingers long after the original acne bump, eczema flare, razor bump, or rash is gone.
PIH is not dangerous, not contagious, and not a true scar in the way most people think of scarring. But it can be stubborn, emotionally frustrating, and difficult to ignore—especially when the dark marks last longer than the condition that caused them in the first place.
For many people with deeper skin tones, that is exactly what makes PIH so exhausting: the breakout, bump, or rash may improve in days or weeks, but the discoloration can stay for months.

Fast Facts

• What is PIH?

  Dark spots or patches that appear after inflammation, irritation, or injury

• Is it a scar?

  No. PIH is excess pigment, not structural scarring

• Who gets it?

  Anyone can develop it, but it is much more common in people with skin of color

• What causes it?

  Acne, eczema, razor bumps, bug bites, burns, picking, irritation, and some cosmetic procedures

• Does it go away?

  Often yes—but it can take months, and deeper PIH can last much longer

• What’s the most important first step?

  Treat the underlying cause of inflammation so new dark spots stop forming

• Does sunscreen matter for dark skin?

  Absolutely. UV light and visible light can worsen PIH

Why PIH Happens

PIH develops after the skin becomes inflamed. That inflammation can come from something obvious, like acne or eczema, but it can also come from irritation that seems “small” in the moment—like picking at a pimple, scratching a rash, or using a product that your skin simply does not tolerate well.

Common Triggers include:

• acne

• eczema

• pseudofolliculitis barbae (razor bumps)

• contact dermatitis

• bug bites

• burns or cuts

• picking or squeezing pimples

• chemical peels, lasers, or other skin procedures

• friction, harsh scrubs, or irritating skincare products

Once the skin is inflamed, the pigment-producing cells—called melanocytes—can go into overdrive and make extra melanin. That pigment then gets deposited in the skin and can remain even after the original inflammation has healed.

That is why PIH is not really its own condition. It is the after-effect of inflammation.

Why PIH Hits Harder in Skin of Color

1. Melanocytes are more reactive

   People with darker skin naturally have melanocytes that respond more strongly to inflammation. That means even mild acne, a bug bite, or a little irritation from a product can leave behind visible pigment.

2. The contrast is greater

   A dark mark tends to stand out more clearly against medium to deep skin tones, especially on the face. Something that may leave little visible change on lighter skin can create a mark that is obvious and long-lasting on darker skin.

3. PIH often lasts longer

   In skin of color, PIH is not just more common—it is often more persistent. The dark spots may be deeper, darker, and slower to fade.

4. The dark marks may become the main problem

   This is one of the most important skin-of-color realities in dermatology: many patients are less bothered by the acne, razor bump, or eczema flare itself than by the dark marks it leaves behind. In some cases, the PIH becomes the real chief complaint.

That is part of why treating skin of color well means treating both the inflammation itself and the pigment it leaves behind.

What PIH Looks Like

PIH usually appears as flat areas of discoloration that follow the pattern of the original rash, acne, or irritation.

People often describe it as:

• “dark spots after acne”

• “marks left behind after a breakout”

• “my razor bumps healed but left stains”

• “the rash went away, but the discoloration stayed”

Unlike active acne or eczema, PIH is usually flat rather than raised. It is not typically itchy,

painful, or draining. It is discoloration left behind after the inflammation is over.

In deeper skin tones, PIH may look like:

• brown

• dark brown

• gray-brown

• blue-gray if the pigment sits deeper in the skin

That blue-gray or slate tone can be a clue that the pigment is deeper and may take longer to improve.

Epidermal vs Dermal PIH: Why Some Dark Spots Fade Faster Than Others

Not all PIH sits in the same layer of skin, and that matters a lot when it comes to treatment and expectations.

Epidermal PIH

This means the pigment is mostly in the upper layer of the skin (the epidermis).

It often appears:

• tan

• light brown

• medium brown

• dark brown

Epidermal PIH is usually the type that responds best to treatment and fades faster over time.

Dermal PIH

This means pigment has dropped deeper into the dermis, often after more significant inflammation.

It may look:

• blue-gray

• slate-colored

• gray-brown

Dermal PIH is usually more stubborn, slower to fade, and harder to treat.

Mixed PIH

Many people have a combination of both, which is one reason dark spots do not all improve at the same pace.

Common Myths

• “Dark spots are scars.”

  Usually, no. PIH is pigment, not a true scar. A scar involves structural damage or texture change in the skin. PIH is discoloration.

• “Dark spots will go away quickly on their own.”

  Sometimes mild PIH does fade without treatment, but many cases—especially in skin of color—last months or longer, especially if the underlying inflammation continues.

• “Sunscreen doesn’t matter for dark skin.”

  It does. Sunscreen is one of the most important tools for preventing PIH from getting darker and helping it fade more efficiently.

• “Home remedies like lemon juice can help fade dark spots.”

  They can do the opposite. Lemon juice, baking soda, harsh exfoliation, and DIY “brightening” tricks can irritate the skin and make PIH worse.

• “If I just use a stronger product, it will fade faster.”

  Not necessarily. In skin of color, irritation can trigger more pigmentation. Sometimes the most effective plan is not the harshest one—it is the one your skin can tolerate consistently.

The Most Common Causes of PIH in Skin of Color

1. Acne

   Acne is one of the most common triggers of PIH. In fact, for many people with skin of color, the dark spots left behind by acne are more distressing than the acne itself.

2. Eczema

   Inflamed, itchy skin can leave behind pigment changes, especially when scratching or rubbing is part of the flare.

3. Razor bumps

   Pseudofolliculitis barbae is a major cause of PIH, especially in Black men and others with tightly curled facial hair.

4. Contact dermatitis and product irritation

   Sometimes the trigger is not a disease—it is a reaction. Fragrances, harsh exfoliants, overuse of active ingredients, or a product that is simply too irritating can all leave behind dark marks.

5. Skin picking

   Picking at acne, squeezing bumps, or scratching irritated skin can dramatically increase

   the risk of PIH.

Why PIH Can Feel More Frustrating Than the Original Condition

PIH is not dangerous, but it can have a real emotional and psychological impact.

For many people, PIH can affect:

• self-confidence

• comfort being photographed

• willingness to leave the house without makeup

• social confidence

• the feeling that their skin is never “clear,” even when the acne or rash is gone

One of the hardest parts is that PIH often makes people feel like they are stuck in a cycle: the acne improves, but the marks stay; then new breakouts appear, and the cycle starts again.

That is why PIH treatment is not just about fading spots. It is also about helping people feel like their skin is moving in the right direction again.

The Most Important Rule in Treating PIH

You have to treat the cause—not just the dark spots

This is the part people often miss.

If acne, eczema, razor bumps, or irritation are still active, new dark spots will continue to form while you are trying to fade the old ones.

So the first step in treating PIH is always to control the inflammation causing it:

• treat the acne

• calm the eczema

• reduce razor bumps

• stop irritating products

• stop picking, squeezing, and scrubbing

You can absolutely work on fading pigment at the same time—but if the inflammation is still happening every day, it becomes much harder to make real progress.

How PIH Is Treated

A good PIH treatment plan usually has three goals:

1. Stop new pigment from forming

That means controlling the underlying inflammatory condition and protecting the skin from UV and visible light.

2. Fade the pigment that is already there

This usually involves topical brightening or pigment-regulating ingredients, and sometimes prescription medications or procedures.

3. Avoid making the skin more inflamed

This is a big one in skin of color. If a treatment irritates your skin too much, it can worsen the very pigmentation you are trying to fix.

The Foundation of Every PIH Routine: Sunscreen

If PIH is one of your main concerns, sunscreen is not optional.

Why sunscreen matters

UV light can darken existing spots and slow down healing. Visible light can also worsen pigmentation in deeper skin tones.

Ideally you want to choose:

• broad-spectrum SPF 30 or higher

• a formula you will actually wear every day

• preferably a tinted sunscreen with iron oxide if PIH is a major concern, since iron oxide helps protect against visible light

A practical note for skin of color

A sunscreen only helps if you are willing to use it consistently. White cast, heaviness, or greasiness are real barriers. It is worth taking the time to find one that feels wearable on your skin tone and skin type.

Ingredients That Can Help Fade PIH

• Hydroquinone

  Hydroquinone is one of the best-known prescription treatments for hyperpigmentation and is often considered a gold standard depigmenting agent.

  It works by slowing melanin production.

  Important notes

  • it is often used in 4% prescription strength

  • it should be used carefully, especially in darker skin, because prolonged misuse can increase the risk of complications such as exogenous ochronosis

  Hydroquinone can be very helpful, but it is not something I would casually recommend people self-manage with random online products.

• Triple combination cream

  This is a prescription combination that often includes:

  • fluocinolone

  • hydroquinone

  • tretinoin

  It can be more effective than hydroquinone alone because it targets pigment, inflammation, and skin turnover all at once.

• Retinoids

  Retinoids such as tretinoin, adapalene, and tazarotene are especially helpful when PIH is tied to acne because they can address both:

  • the acne itself

  • the dark spots left behind

  Retinoids increase skin cell turnover and can gradually help pigment fade.

  The Catch

  Retinoids can also be irritating if started too aggressively, and irritation can worsen PIH. In skin of color, it is often smart to start slowly and build up over time.

• Azelaic Acid

  Azelaic acid is one of the most useful ingredients for PIH because it can help with both pigment and inflammation.

  It is especially appealing when PIH is tied to:

  • acne

  • sensitive skin

  • redness or irritation

  • patients who want an alternative to hydroquinone

  It can be found in both over-the-counter and prescription-strength products depending on the concentration.

• Niacinamide

  Niacinamide can help reduce pigment transfer and is often easier to tolerate than stronger actives. It is a great option for people who want a gentle ingredient that supports both the skin barrier and pigmentation concerns.

• Vitamin C

  Vitamin C can help brighten the skin and support antioxidant protection. It is not the only answer for PIH, but it can be a useful part of a routine if your skin tolerates it well.

• Other ingredients that may help

  Depending on the person and the routine, other ingredients that may be useful include:

  • kojic acid

  • alpha arbutin

  • licorice root extract

  • soy-based brightening ingredients

  • gentle alpha hydroxy acids

  The best routine is not the one with the longest ingredient list. It is the one that actually fits your skin, your tolerance, and the cause of your PIH.

Build a Routine

Morning

1. Gentle cleanser

2. Brightening or anti-inflammatory product if tolerated (for example niacinamide,

vitamin C, or azelaic acid depending on your routine)

3. Moisturizer if needed

4. Tinted broad-spectrum sunscreen SPF 30+

Evening

1. Gentle cleanser

2. Retinoid, azelaic acid, hydroquinone, or another pigment-directed treatment if

prescribed or tolerated

3. Moisturizer

That’s it.

A good PIH routine does not need ten products. In fact, one of the easiest ways to make

PIH worse is to throw too many actives at the skin at once and create more irritation.