Post-Inflammatory Hyperpigmentation
Post-inflammatory hyperpigmentation (PIH) is a very common acquired pigment disorder that follows inflammation or physical injury to the skin. It shows up as flat spots or patches ranging from light brown and dark brown to blue-gray, sitting exactly where the earlier inflammation was: acne, eczema, burns, friction, or invasive cosmetic procedures such as chemical peels, CO2 laser and microneedling.
Although PIH is a harmless response of the immune system and skin cells, it can take a real psychological toll, especially in people with darker skin (Fitzpatrick IV–VI), whose skin is rich in melanin and whose pigment cells react very readily. Rushing to peel the skin or using high-energy thermal lasers to erase PIH while the skin is still chronically inflamed is the leading reason PIH gets worse, spreads and leaves permanent scarring.
At Haute-Derma, our PIH protocol follows one firm rule: calm the inflammation first, then treat the pigment. We combine ingredients that block melanin production and restore the basement membrane with gentle 1064 nm picosecond laser toning, which breaks up excess pigment with a low risk of triggering new inflammation.
How Post-Inflammatory Hyperpigmentation Develops
PIH results from a complex interplay between inflammatory mediators and pigment cells:
- Inflammation Switches On Melanocytes: when skin is injured or inflamed, immune cells release a wave of chemical mediators, including prostaglandins (PGE2, PGF2α), leukotrienes (LTC4, LTD4), histamine, thromboxane B2 and pro-inflammatory cytokines (IL-1, IL-6, TNF-α). These bind to receptors on melanocytes and drive the enzyme tyrosinase to churn out eumelanin.
- Basement Membrane Damage and Pigment Incontinence:
- Epidermal PIH: the extra eumelanin is transferred to and builds up in keratinocytes of the basal and spinous layers.
- Dermal PIH: intense inflammation damages the basement membrane, so pigment cells or melanosomes drop into the dermis (pigment incontinence). Macrophages engulf this melanin and become long-lived melanophages, giving the lesion a blue-gray or blue-black color.
- UV Radiation Makes It Worse: UV light acts as an amplifier. Direct sun generates free radicals (ROS), deepens chronic inflammation and pushes melanocytes in the injured skin to keep producing melanin.
Telling the Types of PIH Apart
| Feature | Epidermal PIH | Dermal PIH |
|---|---|---|
| History | Clear history of dermatitis, acne or injury | History of severe inflammation or deep peeling procedures |
| Color | Light to dark brown | Gray-brown, blue-gray or slate gray |
| Wood's lamp | Contrast clearly enhanced | No enhancement (appears fainter) |
| Where the pigment sits | In epidermal keratinocytes | In dermal macrophages (melanophages) |
| Time to fade on its own | A few months to 1 year with good care | Many years, or permanent without treatment |
| Response to topicals | Responds well to hydroquinone and azelaic acid | Little or no response to topicals alone |
PIH Assessment, Dermoscopy and Classification at Haute-Derma
- History and Assessment of Underlying Inflammation
- Pin down the original trigger (acne, laser, acid peel, burn or contact dermatitis).
- Check whether the inflammation has fully settled: is there still redness (erythema), or has it turned completely into brown or gray pigment?
- Dermoscopy and Wood's Lamp Examination
- Epidermal PIH on dermoscopy: a dark brown pigment network spread evenly along the epidermal ridges.
- Dermal PIH on dermoscopy: irregular blue-gray or gray-brown clouds or granules lying deep below the epidermis.
- Wood's lamp (365 nm): shows how deep the pigment lies, so we can give a realistic estimate of treatment time.
- Skin Barrier Assessment: we measure transepidermal water loss (TEWL) and how reactive the skin is, so barrier repair can be planned before any device treatment.
Our Multi-Layered PIH Treatment at Haute-Derma
Haute-Derma uses a three-phase approach, closely tailored to the depth of the pigment and the health of the skin barrier:
- Calm Inflammation and Repair the Barrier
- Stop all peels and high-energy ablative lasers.
- Use soothing, barrier-restoring ingredients: ceramides, 5% niacinamide, panthenol (vitamin B5) and madecassoside.
- Mesotherapy microinjections or cryo-electroporation with 5% tranexamic acid, which inhibits plasmin and so reduces both redness and melanocyte stimulation.
- Home Topicals to Control Tyrosinase
- We prescribe safe, non-irritating pigment inhibitors: 15–20% azelaic acid, arbutin, kojic acid and vitamin C (L-ascorbic acid or 3-O-ethyl ascorbic acid).
- Long-term, high-strength hydroquinone is kept to a minimum, since irritation can cause new PIH on top of the old and it carries a risk of ochronosis.
- 1064 nm Picosecond Laser Toning for Dermal PIH
- For pigment that has dropped into the dermis (melanophages), we use a 1064 nm picosecond laser in low-fluence toning mode (7–9 mm spot size, 0.6–1.0 J/cm²).
- Ultra-short photomechanical pulses shatter the pigment inside melanophages into very fine particles that the lymphatic system clears naturally, without the heat that would spark fresh inflammation.
- Course: 4–8 sessions, 3–4 weeks apart.
