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

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

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

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.

Procedures for Stubborn PIH

Some cases of PIH need more than topical products, especially when the pigment is deeper or the discoloration is widespread.

Chemical peels

Chemical peels can be helpful for some patients, especially when done by a dermatologist or experienced clinician who understands skin of color.
But they are not automatically gentle just because they are common. If the peel is too aggressive or poorly chosen, it can worsen PIH.

Laser and light-based treatments

Laser treatment can help in select cases of resistant PIH, but it has to be approached carefully in deeper skin tones.
Not every laser is appropriate for every skin type, and poorly selected settings can worsen pigmentation rather than improve it. If laser is being considered, it should ideally be done by someone with real experience treating skin of color.

Oral tranexamic acid

This is an emerging option in some pigment disorders and may play a role in select PIH cases, but it is not a casual first-line fix and should be discussed with a physician.

Skin of Color Treatment Principles That Matter

1. Prevent PIH whenever possible- In skin of color, prevention matters just as much as treatment. That means treating acne, eczema, and razor bumps early—before they leave behind long-lasting marks.
2. Go slowly enough to avoid irritation- More treatment is not always better. A product that is “strong” but leaves your skin inflamed can set you back.
3. Protect against visible light, not just UV- This is one of the most important pearls in pigment management for deeper skin tones. Tinted sunscreen can make a real difference.
4. Be careful with unregulated “skin lightening”-products This is a major safety point. Some products marketed for dark spots or “lightening” may contain:
• mercury
• potent topical steroids
• unsafe hydroquinone concentrations
• undisclosed bleaching ingredients
These can cause serious and sometimes permanent damage.
5. Set realistic expectations- PIH can improve- but it rarely improves overnight. Some pigment fades in a few months. Some takes much longer. The goal is steady progress, not instant perfection.

How long does PIH take to fade?

This is one of the most important questions patients ask, and the honest answer is: 
It depends on how deep the pigment is, how well the underlying inflammation is controlled, and how consistent the treatment plan is.
In general:
• mild epidermal PIH may improve over weeks to months
• more stubborn surface pigment may take several months
• deeper dermal PIH may last many months to a year or longer
That is one reason it helps to think of PIH treatment as a long game. You are trying to calm the skin, prevent new spots, and slowly fade the pigment that is already there.

When to See a Dermatologist

It is worth seeing a dermatologist if:
• dark spots are not improving after several months
• you are not sure whether the discoloration is PIH, melasma, or another pigment
disorder
• the acne, eczema, or razor bumps causing the PIH are not controlled
• the marks are blue-gray, widespread, or especially stubborn
• over-the-counter products are causing irritation
• you are considering hydroquinone, chemical peels, or laser treatment
• the pigmentation is affecting your confidence, social life, or mental health
• you are thinking about using a “skin lightening” product and want help choosing something safe
For people with skin of color, it can be especially helpful to see a dermatologist who is comfortable treating pigment disorders in deeper skin tones.

Things to Remember

|

Things to Remember |

If you have skin of color and are dealing with dark spots, I would want you to remember a few things:
• Dark spots after inflammation are common, and you did not do anything wrong
by getting them.
• The original trigger matters just as much as the pigment itself.
• Sunscreen is part of treatment, not an optional extra.
• You do not need to punish your skin to make progress.
• PIH often gets better—but patience, consistency, and a gentle plan matter.
Previous
Previous

Vitiligo

Next
Next

Melasma in Skin of Color