“Dark spots,” “melasma,” “PIH” — these terms get used interchangeably, but they're not the same thing, and telling them apart helps you treat them correctly. Here's a plain-English guide.
Post-inflammatory hyperpigmentation (PIH)
The most common type on melanin-rich skin. PIH is the flat dark mark left behind after inflammation — a pimple, a bug bite, eczema, an ingrown hair, or a scrape. It appears exactly where the injury was, and it fades over time with the right care.
Melasma
Melasma appears as larger, symmetrical patches, usually on the cheeks, forehead and upper lip. It's often driven by hormones (pregnancy, birth control) and is strongly worsened by sun and heat. It tends to be more stubborn and recurring than PIH.
“Dark spots” / sun spots
“Dark spots” is really an umbrella term. Beyond PIH, it includes sun-induced spots that build up over years of UV exposure — smaller, defined spots on the areas that get the most sun.
How to tell them apart
- Follows a blemish or injury? Likely PIH.
- Large symmetrical patches, worse in the sun, possibly hormonal? Likely melasma.
- Scattered small spots on sun-exposed areas? Likely sun spots.
Do they need different treatment?
The gentle fundamentals help all three: brightening actives (Vitamin C, niacinamide, kojic acid) and daily SPF. The big difference is that melasma is especially sun- and heat-sensitive and often needs professional guidance — so if patches are widespread, symmetrical, or not responding, see a dermatologist.
For PIH and everyday dark spots, a consistent routine like IYASA's Brightening Set for Melanin-Rich Skin — SGS lab-tested, no hydroquinone — is a great place to start. Read more on fading dark spots and treating hyperpigmentation.