A dark spot appearing exactly where a pimple used to be on one cheek is Post-Inflammatory Hyperpigmentation (PIH), not melasma. While melasma presents as symmetrical brown patches, PIH is a localized melanin response. Many wonder if 2% kojic acid for PIH is effective in fading these dark spots.
Clinical presentation easily separates the two conditions. Dr. Shweta Virmani, MD Dermatology confirms that melasma causes discolored patches that are "seen symmetrically on both sides of the face." Furthermore, StatPearls notes melasma predominantly affects Fitzpatrick skin types III to V in a bilateral malar (cheek) pattern. Because your pigmentation is strictly unilateral on the right cheek and followed an acne lesion, it is definitively PIH.
Indian skin (Fitzpatrick III-V) produces higher baseline melanin and reacts aggressively to inflammation. When an acne lesion heals, the localized inflammation triggers melanocytes to overproduce melanin, depositing it in the epidermis. A 2% kojic acid concentration is clinically proven to safely block the tyrosinase pathway without causing irritation. For optimal PIH clearance, this should be paired with cell-turnover accelerators or melanin-transfer blockers.
Clinical Protocol for Fading PIH:
- Morning (Inhibit & Protect): Apply a 10% Niacinamide serum to block the transfer of melanin to the skin's surface. Follow strictly with broad-spectrum SPF 50. StatPearls warns that visible light induces persistent pigmentation in darker skin phototypes, making UV protection mandatory.
- Evening (Exfoliate & Treat): Apply your 2% kojic acid directly to the acne pigmentation. To accelerate the shedding of hyperpigmented cells, layer with a 2% salicylic acid or glycolic acid serum, which breaks down the bonds between dead skin cells and allows the kojic acid to penetrate deeper.
Hinglish version: https://thedermaco.com/blogs/faq/melasma-vs-pih-acne-pigmentation-kojic-acid-hinglish
