Not All Darkening Is The Same
Hyperpigmentation is the umbrella term for any area of skin that appears darker than the surrounding tissue. But the mechanism — and therefore the treatment — differs fundamentally across the three main types.
Type 1: Melasma
Melasma is a chronic, hormonally-driven pigmentation condition characterised by symmetrical brown-grey patches, typically on the cheeks, forehead, upper lip, and bridge of the nose. It is driven by oestrogen and progesterone stimulation of melanocytes — which is why it's far more common in women, particularly during pregnancy ("chloasma") or while using combined oral contraceptives.
- UV dramatically worsens melasma — even brief exposure triggers relapse
- HEV blue light also triggers melanogenesis in melasma-prone skin
- Treatment hierarchy: Triple combination cream (tretinoin + hydroquinone + corticosteroid) → tranexamic acid → azelaic acid 15–20% → kojic acid → chemical peels (with extreme caution in darker phototypes)
- Non-negotiable: Daily SPF with iron oxides, regardless of weather or sun exposure
Type 2: Post-Inflammatory Hyperpigmentation (PIH)
PIH is melanin deposition in response to inflammation. Any inflammatory trigger — acne, eczema, burns, waxing, aggressive chemical peels — can cause melanocytes to overproduced pigment that then deposits in the epidermis or dermis.
- Epidermal PIH (tan-brown): Responds well to topical depigmentation agents
- Dermal PIH (grey-blue): Much harder to treat; laser may be required
- First priority: Treat and prevent the inflammatory trigger
- Treatment: Niacinamide + Vitamin C + azelaic acid → retinoids → chemical peels
- Higher risk: Fitzpatrick types IV–VI develop darker, more persistent PIH
Type 3: Post-Inflammatory Erythema (PIE)
PIE is often confused with PIH but is mechanistically different — it is vascular (dilated capillaries), not melanin-based. Appears as pink-red marks left after acne or inflammation, particularly in lighter Fitzpatrick types. It does not respond to tyrosinase inhibitors (Vitamin C, niacinamide) the way PIH does.
- Treatments that work for PIE: Azelaic acid (vascular anti-inflammatory), niacinamide (vasoconstrictive), green tea extract, tranexamic acid, red LED light therapy
- Fastest clearance: Vascular laser (IPL, pulsed dye laser) — available at dermatology clinics
Universal Rules for All Hyperpigmentation
| Rule | Why |
|---|---|
| Daily SPF (50+ with iron oxides) | UV triggers tyrosinase — all brightening efforts are undone without protection |
| No picking or pressing blemishes | Mechanical trauma directly triggers melanocyte activation |
| Patience: 3–6 month timeline | One full cellular turnover cycle is 28+ days; pigment must shed from each layer |
| Treat the inflammation first | Active inflammation continuously triggers new pigment — treat the cause, not the consequence |
For the biology behind pigment production, see Melanogenesis. For brightening ingredient science, see Antioxidants & Vitamin C.