Post-inflammatory hyperpigmentation (PIH)

By Dr. Doaa Al Rawad, Dermatologist
Updated 13 Oct 2026 · 3 min read

What PIH is

DermNet describes post-inflammatory hyperpigmentation as temporary pigmentation that follows an injury, such as a burn, or an inflammatory skin problem, such as dermatitis or an infection. Once the original problem settles, a flat brown, grey or darker mark can remain in the same place.

Common starting points include acne spots, eczema, insect bites, friction, waxing, threading, picking, an irritating product and cosmetic procedures. PIH can appear anywhere on the body, and its shape often follows the earlier spot or rash.

Why it matters for darker skin tones

PIH can affect anyone, but DermNet notes that in darker-skinned people the colour tends to be more intense and to last longer than in lighter skin. That is one reason dermatologists plan lasers and peels carefully for brown and deeper skin tones, especially in strong sun.

How it differs from melasma

Melasma usually forms fairly symmetrical patches on both sides of the face without an obvious injury beforehand. PIH follows something that happened to the skin. The two can exist together, and the same face may also have sun spots. A dermatologist diagnoses PIH from a careful history and an examination of the skin, which matters because the wrong treatment can irritate and darken the area further.

Care that helps

The first step is to treat what caused the inflammation: control acne, calm eczema and stop the product that stings. Do not pick, scrub or bleach the mark. If the mark is on exposed skin, DermNet advises daily SPF 50+ broad-spectrum sunscreen to limit darkening from ultraviolet light.

Fading is usually gradual. If a mark is spreading, not improving, or you are unsure what it is, ask a dermatologist, who may discuss topical options suited to your skin. After any procedure, follow the treating clinician's aftercare and apply sunscreen only to healed skin.