What post-acne hyperpigmentation is

When a spot becomes inflamed, the skin's pigment cells can respond by producing extra melanin. Once the spot heals, that pigment stays behind as a flat brown, tan or grey-brown mark. Dermatologists call this post-inflammatory hyperpigmentation , or PIH. It is not a scar: the skin surface is smooth, and with time and care the colour usually fades completely.

PIH is particularly common in people with medium to darker skin, including many East Asian, South Asian, Middle Eastern, Latin and Black patients, because their pigment cells react more strongly to inflammation. That is why it is one of the most frequent concerns we see in Seoul, both in Korean patients and in visitors. Our acne and breakouts guide covers the acne side of the story.

Why marks can appear after acne treatment, too

Patients are sometimes surprised to develop new dark marks after an acne procedure. Any treatment that causes inflammation can trigger PIH in pigment-prone skin: aggressive extraction, strong chemical peels, high-energy lasers, microneedling, or simply irritation from starting retinoids too quickly. Sun exposure in the weeks after treatment makes it more likely.

This does not mean acne treatment should be avoided, because untreated acne creates far more marks. It does mean the plan should be gentle and paced, with sunscreen from day one and settings chosen with your skin tone in mind. In Korea, where laser toning and extraction are widely offered, it is worth asking how a clinic adjusts treatment for PIH-prone skin.

PIH, red marks or scars? Telling them apart

Not every mark after acne is PIH. Red, pink or purple flat marks are usually post-inflammatory erythema , caused by small dilated blood vessels rather than pigment; they respond to different treatments, such as vascular lasers or light where suitable, and to time. Dented or raised marks are scars , which need resurfacing or collagen-building treatment such as those described on our acne scar removal page.

A doctor can usually tell the difference by looking closely, pressing on the mark and using imaging such as Mark-Vu . Getting this right matters, because treating red marks or scars as if they were pigment wastes time and money, and some pigment treatments can irritate already inflamed skin.

Treatment options compared

Most PIH improves with a combination of acne control, sun protection and topical treatment. The table summarises the main options. Prescription creams such as hydroquinone or tretinoin should be used under medical supervision and for limited periods, because irritation can itself create new pigment.

For marks that persist despite good skincare, low-fluence 1064 nm laser toning or carefully set picosecond laser can help break up pigment gradually. The key is a conservative approach: several gentle sessions spaced one to two weeks apart, rather than one strong session that inflames the skin again.

How Obliv plans PIH treatment in Seoul

At the Myeongdong Premium Branch, the doctor first checks whether acne is still active, because new spots will keep creating new marks. If it is, the plan starts with acne control: prescription topicals, gentle medical extraction where helpful, or calming treatments such as LDM skin regeneration. Using our Skin Architecture method, pigment in the epidermis and upper dermis is then treated separately from redness and from texture.

Where laser is appropriate, we favour gradual laser toning at settings that respect your skin type, combined with home care you can continue after you fly. If texture or shallow scarring is part of the picture, Pico Fraxel may be added later, once inflammation and pigment are under control. Every session is recorded in your Skin Library.

• Acne & Breakouts
• Acne Scar Removal
• Melasma & Dark Spots
• Korean Acne Protocol for Adults

Home care that helps marks fade

Good home care is the foundation of PIH treatment. Use a gentle cleanser, a non-comedogenic moisturiser and a broad-spectrum sunscreen every morning, reapplying when outdoors. Tinted sunscreens containing iron oxides also block visible light, which can darken pigment in some people. Avoid scrubs, harsh toners and picking, all of which re-inflame the skin.

Introduce one active ingredient at a time: azelaic acid, niacinamide or a retinoid, as your doctor advises. If skin stings, burns or peels heavily, scale back, because irritation is the enemy of fading pigment.

• Sunscreen every day, even indoors near windows and on cloudy Seoul days.
• Hands off: do not squeeze or pick spots or scabs.
• Patch-test new products and add them one at a time.
• Take monthly photos in the same light to track real progress.

A realistic timeline

PIH fades gradually. Lighter, superficial marks often improve noticeably within two to three months of good care, while deeper or darker marks can take six to twelve months or longer. Laser toning can speed this up for some people, but it is not instant, and treating too aggressively risks rebound darkening.

If you are visiting Seoul for a short trip, a realistic aim is to start the right plan, perhaps with one or two gentle laser sessions, and continue topical care and sunscreen at home. We provide a written plan you can share with your own doctor.

When to see a dermatologist, at home or in Seoul

See a doctor if marks are not improving after three months of sunscreen and gentle care, if you keep getting new acne, or if you are unsure whether a mark is pigment, redness or a scar. Any spot that is changing, bleeding, itchy or unlike your other marks should be checked by a dermatologist for other causes, including skin cancer.

If you are planning broader pigment treatment, our guides to Korean lasers for Asian pigmentation and the best season for pigmentation lasers explain timing and options.

Frequently asked questions

Related treatments and guides

Keep reading

• Korean Laser for Asian Pigmentation in Seoul
• Best Season for Pigmentation Laser in Seoul
• Korean Acne Protocol for Adults
• Acne Scar Consultation in Myeongdong

Sources

1. DermNet – Postinflammatory hyperpigmentation
2. Cleveland Clinic – Hyperpigmentation: What it is, Causes & Treatment
3. American Academy of Dermatology – Acne scars: Consultation and treatment
4. American Academy of Dermatology – How to select a sunscreen