Why dark marks linger on deeper skin, and how to fade them safely
Post-inflammatory hyperpigmentation is one of the most common concerns in skin of color. Here is what the research says about causes, prevention and treatment.
- Post-inflammatory hyperpigmentation (PIH) is more common and longer-lasting in skin of color; one acne survey found it in 65.3% of African American patients.
- Treating the underlying inflammation early and wearing daily SPF 30+ sunscreen are first steps; tinted sunscreen adds visible-light protection.
- Irritating or overly aggressive treatments can make dark marks worse.
A breakout clears, a bug bite heals, a patch of eczema calms down, and a dark mark stays behind for months. Dermatologists call this post-inflammatory hyperpigmentation, or PIH: extra pigment the skin produces after inflammation or injury.
Why it's more common in melanin-rich skin
A widely cited 2010 review by Davis and Callender describes PIH as affecting people with skin of color more often and more severely. It points to a survey of patients with acne by Taylor and colleagues (2002), which found PIH in:
- 65.3% of African American patients
- 52.7% of Hispanic patients
- 47.4% of Asian patients
For many people, the mark bothers them more than the breakout that caused it.
Not all dark marks are the same
The same review describes two kinds. Epidermal PIH sits near the surface, looks tan to brown, and fades over months to years. Dermal PIH sits deeper, looks blue-gray, and may fade very slowly or become permanent. That's one reason a professional assessment matters before choosing treatment.
Light you can see plays a role too
Sunscreen is usually discussed in terms of ultraviolet (UV) light, but visible light matters for deeper skin. In a 2010 study by Mahmoud and colleagues, visible light caused darker, longer-lasting pigmentation in skin types IV to VI, while lighter skin types showed no pigmentation at the same dose. A 2020 review in Photochemical & Photobiological Sciences notes that standard UV filters don't block visible light, and that tinted sunscreens containing iron oxides helped reduce melasma relapse.
What helps, according to the research
- Treat the cause first. Davis and Callender write that managing PIH "should begin first with addressing the underlying inflammatory dermatosis." Calm the acne or eczema, and fewer new marks form.
- Protect every day. The review recommends daily broad-spectrum sunscreen of SPF 30 or higher. A tinted formula adds protection from visible light.
- Start early. The authors note that treating PIH early may help it resolve faster.
- Avoid irritation. Over-aggressive treatment can make PIH worse. The review cautions that overusing hydroquinone can cause a different discoloration called exogenous ochronosis, and that some lasers can cause new pigment problems in darker skin.
Fading ingredients discussed in the review include azelaic acid, retinoids, niacinamide and vitamin C, along with carefully selected peels. Which of these is right for you depends on your skin, the type of PIH and how well your barrier tolerates them.
Blue Elephant™ is built around brightening with patience and protection: calm first, protect daily, then correct gradually. Red Cardinal™ addresses breakouts in a way designed to limit the marks they leave.
Sources
- Davis EC, Callender VD. Postinflammatory hyperpigmentation: a review of the epidemiology, clinical features, and treatment options in skin of color. J Clin Aesthet Dermatol. 2010;3(7):20–31. Source
- Taylor SC, Cook-Bolden F, Rahman Z, Strachan D. Acne vulgaris in skin of color. J Am Acad Dermatol. 2002;46(2 Suppl):S98–S106. Source
- Kohli I, Lim HW, Hamzavi IH, et al. Visible light in photodermatology. Photochem Photobiol Sci. 2020. (Reviews Mahmoud BH et al., J Invest Dermatol. 2010.) Source
This article is for education only and is not medical advice. Talk with a licensed clinician about your own skin.
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