Blog Post

Most people think dark spots appear because the skin is producing “too much pigment.”
The reality is more complex.
Post-Inflammatory Hyperpigmentation (PIH) is the skin’s response to inflammation—not the original problem itself.
Whether the trigger is:
Acne
Eczema
Chemical burns
Aggressive laser treatments
Excessive exfoliation
Skin picking
The common pathway is inflammation.
What Happens Beneath the Skin?
When inflammation occurs, skin cells release signaling molecules such as:
• Prostaglandins
• Leukotrienes
• Cytokines
• Reactive Oxygen Species (ROS)
These inflammatory mediators stimulate melanocytes—the cells responsible for producing melanin.
In response, melanocytes increase melanin production as a protective mechanism.
The result?
Excess pigment is deposited in the affected area, creating a dark spot long after the inflammation has resolved.
Why Do Some Dark Spots Last for Months?
The answer depends on where the pigment is located.
Epidermal PIH
Pigment remains in the upper layers of skin
Appears brown or tan
Responds relatively well to treatment
Dermal PIH
Pigment drops deeper into the dermis
Appears grey, blue-grey, or slate-colored
Much harder to treat
May persist for years
This is why two patients with similar acne can have very different outcomes.
Why Is PIH More Common in Darker Skin Tones?
Individuals with Fitzpatrick Skin Types IV–VI naturally have more active melanocytes.
These melanocytes respond more aggressively to inflammatory signals, making post-inflammatory pigmentation more likely and often more persistent.
This is why preventing inflammation is especially important in darker skin types.
The Biggest Mistake Patients Make
Many people focus only on removing pigmentation.
But the real strategy is:
Control inflammation first.
If acne, irritation, or barrier damage continues, new pigmentation will keep forming regardless of how many brightening products are used.