Hyperpigmentation refers to spots or patches that are darker than the surrounding skin and is a result of problems in the production and distribution of pigment in the skin. Several different conditions fall under the umbrella of hyperpigmentation, such as:

• Postinflammatory hyperpigmentation (PIH)
• Melasma
• Liver spots

For acne patients, postinflammatory hyperpigmentation is the most common, and that’s what I focus here. Many people call post-acne PIH as acne marks or acne scars. They show as red or darkened dots in areas that used to have active acne.

I’ll also refer to studies done on other hyperpigmentation disorders. The same treatments are likely to be also effective for PIH as the mechanisms behind them are similar.

Brief description of PIH

Postinflammatory hyperpigmentation results from overproduction of melanin or irregular distribution of it in the skin. This shows up as spots that are darker than the surrounding skin. Inflammatory damage can interfere with the mechanisms that regulate pigment production and distribution in the skin, and that’s why PIH is a common consequence of acne and other inflammatory skin conditions. The darker spots occur at the same area pimples did, and that’s why PIH is sometimes called post-acne marks.

Postinflammatory hyperpigmentation can take different appearance depending on how deep in the skin it happens. PIH at the top layer of the skin (epidermis) is usually tan/reddish, brown or dark brown. When it occurs deeper in the skin (dermis) PIH marks can appear bluish-gray.

Prevalence

PIH is far more common in darker skin colors, with studies showing 5 to 10 times higher prevalence in blacks than in whites.

Prevention: sun protection + reduce inflammation

Since PIH is a result of inflammatory damage, it’s important to minimize inflammation in the skin and apply antioxidant cream every morning and evening. Sunscreen is another important step. Sun exposure increases pigment production and can worsen the situation. Most studies recommend even people with darker skin to use a sunscreen with SPF 30 or higher.

What to expect

Hyperpigmentation is notoriously persistent. Even effective treatments take weeks to months to start working. Most studies I reviewed ran between 8 and 12 weeks, and while many treatments produce a noticeable reduction in hyperpigmentation, I wouldn’t call the results stunning. It can take 6 to 12 months to get good results.

So when you get started, expect to be at it for a while and go in with realistic expectations. Studies show the treatments work, but only if you stick with them.