You cleared the breakout. You followed your routine. But weeks later, the spot is gone and a dark mark has taken its place.
If you have melanin-rich skin, you know this pattern well. That stubborn dark mark is called post-inflammatory hyperpigmentation, or PIH. It is one of the most common and most frustrating skin concerns for women with dark skin and it is almost never talked about.
What is PIH?
Post-inflammatory hyperpigmentation is the darkening of skin that occurs after any form of inflammation or injury. When your skin experiences trauma, a breakout, a cut, an insect bite, or even aggressive skincare, it triggers an inflammatory response.
In melanin-rich skin, that response includes a surge in melanin production. The inflammation clears. But the excess melanin stays behind, leaving a dark patch that can persist for months or even years.
PIH is not scarring. It is pigmentation. And that distinction matters because pigmentation can be treated.
Why melanin-rich skin is more vulnerable
All skin types can develop PIH. But women with Fitzpatrick V and VI skin tones experience it more frequently, more intensely, and for longer.
The reason is the same protective mechanism that makes melanin-rich skin resilient. Melanocytes in darker skin tones are more active and more reactive. Any stimulus, inflammation, heat, UV exposure, or even certain skincare ingredients, can trigger an outsized melanin response.
This is why treatments that work for lighter skin tones can actually worsen PIH on darker skin. Certain lasers, chemical peels and even some exfoliants cause enough inflammation to trigger a new wave of hyperpigmentation.
What triggers PIH?
The most common causes include acne and breakouts, skin injuries and cuts, insect bites, eczema and psoriasis flares, aggressive skincare treatments, sun exposure following inflammation, and waxing or threading.
Even stress can play a role. Cortisol increases inflammation, which increases melanin production.
How is PIH treated?
Traditional treatments for PIH include niacinamide, which inhibits the transfer of melanin to skin cells, vitamin C, which interrupts melanin synthesis, azelaic acid, which reduces tyrosinase activity, and sun protection, which prevents existing pigmentation from darkening further.
These ingredients work. But they work slowly and they address the symptom, not the underlying cellular mechanism.
How red light therapy treats PIH
Red light therapy addresses PIH at the cellular level, targeting the enzyme responsible for melanin production.
A 2024 systematic review published in Photodermatology, Photoimmunology & Photomedicine found that red light at 630nm and near-infrared at 850nm modulate tyrosinase activity, the enzyme that drives melanin synthesis, significantly reducing melanin content with consistent use.
Crucially, red light therapy also reduces inflammation. Since inflammation is the trigger for PIH in the first place, reducing it proactively helps prevent new dark marks from forming.
A clinical study from December 2024 found that near-infrared light at 850nm was effective not only in preventing post-inflammatory hyperpigmentation but also in treating existing hyperpigmentation, making it one of the few treatments that works on both prevention and correction simultaneously.
The Lumara approach to PIH
The Lumara protocol pairs red and near-infrared light with niacinamide serum for maximum results on PIH.
Apply niacinamide serum to clean skin. Use the Lumara mask in Red and Near-Infrared mode for 15 minutes. Follow with moisturiser. Repeat Monday, Wednesday and Friday.
The niacinamide works on the surface to inhibit melanin transfer. The red and near-infrared light works beneath the surface to reduce tyrosinase activity and inflammation. Together, they address PIH from two directions simultaneously.
Most users notice visible improvement in existing dark marks after 6 to 8 weeks of consistent use.
The bottom line
PIH is not something you have to live with. It is a treatable condition with a clear biological mechanism and red light therapy is one of the most effective and safest tools available for melanin-rich skin.
No burns. No risk of worsening. Just light, working with your skin at the cellular level.
Lumara. The light therapy ritual for melanin-rich skin.