Everything You Need to Know About Post-Inflammatory Hyperpigmentation

If you suffer from acne or other skin conditions, dark spots and splotches can be standing between you and a clear, glowing complexion. These discolorations are called hyperpigmentation, and they can be hard to fade.

One type of hyperpigmentation is PIH, which occurs when your skin becomes inflamed. It can occur in people of all ages, genders, and races/ethnicities but tends to be more severe and last longer in those with darker skin.

What is PIH?

PIH is a common skin discoloration that develops as a result of inflammation. Inflammation stimulates melanocytes to produce and transfer pigment (skin color) into skin cells as a protective mechanism to heal damaged tissues. This process can sometimes go into overdrive and leave behind dark spots of discoloration. PIH often occurs after heat burns, acne, psoriasis, eczema, and other skin diseases, as well as chemical peels, laser therapy, and sun damage.

Unlike scars, PIH doesn’t form in deep layers of the skin but is usually on the surface of the epidermis or dermis. Depending on your skin tone, PIH can be caused by any inflammatory condition ranging from pink to red, purple to brown, or black.

PIH can appear in all skin types, but it tends to show up more prominently in people with Fitzpatrick skin types III-V (skin of color). This is because skin of color has more pigmentation or melanin, making the skin sensitive to irritation. This can lead to a more rapid development of discoloration in those with darker complexions.


Hyperpigmentation happens when your skin makes too much of the pigment that gives it color, especially during an injury or when an inflammatory skin condition occurs. In answering the question “What is post-inflammatory hyperpigmentation?” first, you must know when it appears. PIH usually appears as flat areas of discoloration that are purple, brown, or black (depending on your skin tone) and is more common in those with darker skin.

People with more melanin produce more skin-darkening pigment if they are harmed or exposed to inflammation. Acne, psoriasis, eczema, burns, and even pregnancy can lead to PIH. In addition, certain drugs and medical disorders may be the cause.

It is more prevalent in women, but men can get it, too. It can show up at any age and can affect all skin types, but tends to be more severe in those with darker complexions. It can also be more persistent in some people. Often, the dark spots will fade with time, but you may need a dermatologist to help lighten them and prevent them from returning. This is why using products that contain tyrosinase inhibitors to prevent more melanin production can be helpful.


When PIH occurs, it forms flat areas of pigmentation that can appear pink, red, purple, brown, or black, depending on skin tone and depth. The condition typically affects women and men of all ages but tends to occur more often in those with darker skin tones.

Inflammation is a natural body response to protect itself from germs, toxins, diseases, and injuries by sending white blood cells and other inflammatory agents to the site. Those inflammatory mediators can also trigger melanocytes to release excessive pigment granules, darkening the affected area.

Inflammation can occur on the face, neck, and other body parts. Those dark marks are sometimes called post-acne marks and can remain long after the initial acne blemishes have subsided, leaving behind discolored pigmentation spots. The dark marks can remind of past blemishes and have been known to make former acne sufferers feel self-conscious. While most PIH fades with time, it can take months to years for those marks to clear up completely. Picking, rubbing, or scratching the affected areas can prolong their appearance and aggravate the skin, so it is essential to avoid those behaviors.


The darkening of the skin that is associated with PIH typically resolves once the inflammation clears. In some cases, however, the connection between a scar or other discoloration and the initial inflammatory event can be unclear, such as when acne lesions disappear, but PIH persists. In this case, it may be a good idea to visit a dermatologist for a skin examination and to discuss possible treatments.

Chemical peels can effectively fade PIH, especially in darker skin tones. However, it is essential to be very careful in choosing the right chemical peel and to precondition the skin with hydroquinone and tretinoin several weeks before a peel. Laser treatment is also a potential option, but a trained dermatologist must use specific lasers with specific settings to avoid complications or worsening of the pigmentation.

The most common way to fade PIH is with topical skin lightening agents, including prescription products such as 2%-6% hydroquinone; combination fluocinolone acetonide, hydroquinone, and tretinoin; azelaic acid; and oral tranexamic acid. Also, a custom skincare routine that includes exfoliation and sun avoidance will help to fade the pigmented patches of the skin.


A common skin condition, PIH typically shows up as dark spots on the skin that follow inflammation and healing. Generally, these dark spots appear on the face and body and vary in color depending on the severity of the underlying issue. It can be caused by almost anything that irritates, inflames, or damages the skin, including acne, cuts and cold sores, eczema (atopic dermatitis), psoriasis, and other conditions such as melasma, hyperpigmented pityriasis versicolor, pseudofolliculitis barbae, and lichen planus. PIH can occur in all Fitzpatrick skin types but is more visible in those with darker skin tones.

While PIH fades over time, it’s best to avoid the sun as it can aggravate symptoms and prolong healing. 

Generally, dark spots caused by PIH will fade on their own over time.

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