Melasma, Sun Spots or Post-Inflammatory Hyperpigmentation: How to Tell Them Apart

Why the type of dark spot matters

You look in the mirror and see brown patches that were not there a few years ago, or dark marks where old pimples used to be. Most people call all of it dark spots. Doctors usually sort them into a few groups, and three of the most common are melasma, sun spots and post-inflammatory hyperpigmentation (PIH).

The label matters because each one has different triggers and responds differently to treatment. The AAD notes that melasma can be mistaken for another skin condition, and that what looks like an age spot could be skin cancer. Picking a treatment before you know which one you have can waste money or make the problem darker.

This guide is about telling them apart. How sunscreen, creams, peels and lasers compare is covered in hyperpigmentation creams vs. laser.

Melasma: patches tied to sun and hormones

The AAD describes melasma as blotchy patches and freckle-like spots that are darker than your natural skin. They are usually tan, brown or grayish brown, and can look bluish gray in darker skin. They tend to appear on the cheeks, forehead, chin and above the upper lip, usually on both sides of the face. The AAD notes that melasma typically feels flat.

Triggers include sunlight, tanning beds, the hormone changes of pregnancy, birth control pills, some medicines that make skin more sensitive to sunlight, and thyroid disease. A StatPearls review adds visible light, especially in darker skin. The AAD says melasma is much more common in women than men, and that risk is higher for women ages 20 to 40 and for people with medium or dark skin. Many people notice it gets darker in summer and fades in winter.

Melasma is not cancer and is not a sign of skin cancer, according to the AAD. It may fade after a pregnancy ends or after stopping a medicine that triggered it, but it can also last for years. The melasma glossary entry has a short definition, and Laser Eraser's melasma treatment page describes how the practice approaches it.

Sun spots: marks where the sun hits most

Sun spots are what the AAD calls age spots, and some people call them liver spots. The AAD says they appear on areas of the body that the sun's rays often hit, such as the face and hands. MedlinePlus, from the National Library of Medicine, lists them among the skin changes that come with aging and gives the medical term as lentigos.

Melasma is typically a matching pattern on both sides of the face, while sun spots follow where the sun has hit. The AAD says age spots can return after treatment, and that protecting your skin from the sun is how you prevent that.

There is one important warning. The AAD recommends a skin exam by a dermatologist before you treat age spots, because a spot that looks like an age spot could be skin cancer. If a spot is new, changing, bleeding, itching or irregular, the guide get a spot checked before laser explains what to look for. Once a dermatologist has cleared a spot, pigment spot removal covers the cosmetic options at Laser Eraser.

Post-inflammatory hyperpigmentation: a mark left by inflammation

PIH is a dark spot or patch that shows up where your skin was inflamed or hurt. The AAD lists common causes: a pimple or patch of psoriasis clearing, a bite, cut or burn healing, some medicines, and skin or hair products that irritate the skin. A StatPearls review adds that skin procedures can trigger it too, and that it is more common and more severe in darker skin.

The clue is history. PIH sits where something happened to your skin first, such as a pimple, a scrape or a rash. The AAD says that once the cause is found and stopped, many spots clear on their own. A spot a few shades darker than your skin usually fades within 6 to 12 months, while deeper slate blue or gray pigment can take years. Laser Eraser's hyperpigmentation page covers treatment for marks that linger.

Why laser plans differ for each one

Because these three behave differently, the role of laser differs too. Here is how official sources describe it:

• Melasma. A StatPearls review calls melasma chronic and relapsing. It describes a conservative approach that saves lasers for selected stubborn cases, only after sunscreen and creams have been optimized, to limit dark marks and rebound darkening. The AAD says a few studies found that adding laser helped people already using medicine and sun protection, and that treatment cannot make melasma go away forever.
• Sun spots. The AAD says one or two laser treatments can treat age spots quickly, with longer-lasting results than a fading cream. Lasers can cause crusting or temporary darkening of the spots.
• PIH. A StatPearls review says lasers, including picosecond lasers, have been used for these marks but should be used cautiously, because they can cause irritation and more hyperpigmentation.

Getting the right diagnosis

The AAD says a dermatologist can often diagnose melasma by looking closely at the face and neck, sometimes with a Wood's lamp or a dermatoscope that shows how deep the pigment goes. If a spot could be another condition, a small skin sample (a biopsy) may be taken.

Before any visit, write down when the spots appeared, whether they began during pregnancy or after starting a birth control pill, whether they darken in summer, what medicines and products you use, and whether the spots followed acne or an injury. Those answers often point to the right group. At Laser Eraser, a free consultation starts with a provider examining your spots, and the practice's melasma page notes that telling melasma apart from sun damage or post-inflammatory marks changes the plan.

Expect honesty about limits, too. The same page says melasma is managed rather than simply removed, that laser alone is rarely the whole answer, and that daily sun protection is a core part of any plan. If laser is not the right first step for your spots, a careful provider should say so.