The Question Left by Koo Sung-hwan’s Sunscreen Scene: Why Does Melasma Remain After Summer?

In an episode of MBC’s ‘I Live Alone’ broadcast on May 17, 2024, Koo Sung-hwan’s appearance while applying sunscreen was particularly striking. White cream covered much of his face on screen, and the broadcaster also released the scene as an official clip titled “UV Protection.” Thinking of that scene naturally raises a question: if you apply sunscreen diligently, will existing melasma and blemishes disappear as well? [1·2]

For people concerned about melasma, autumn is a curious season. The heat of the sun has eased, but the brown patches in the mirror remain. The sunscreen applied throughout summer may seem to have made no difference, leaving many to wonder whether they need a stronger treatment. But the effects of UV protection and the effects of treating existing pigmentation are not the same thing. Sunscreen is an important foundation of treatment, while the treatment needed depends on the nature of the spots. [3·4]

Are all brown patches on the cheeks melasma?

If small brown spots have been present since childhood and become darker during seasons with greater sun exposure, they may be freckles. By contrast, relatively broad brown or grayish patches on the cheekbones, cheeks, or forehead suggest melasma. In addition to sunlight, hormonal changes and genetic factors are involved in melasma. It is not a condition experienced only by pregnant people; it can also occur in men. These features are clues, however, not criteria for confirmation based on a photograph alone. [3·5·6]

The term ‘age spots’ also warrants a closer look. Lentigines, which are flat brown spots, and seborrheic keratoses, whose surfaces become raised or rough, are different lesions. When brown spots that develop with age are casually grouped together, it is easy to assume that they require the same treatment. But topical medications suited to melasma, lasers used for individual pigmented lesions, and treatments that remove raised lesions have different purposes. At the first consultation, the priority should be identifying what is to be removed, rather than simply how to remove it. [6·7·8]

Why does melasma become darker even when I apply sunscreen?

Melasma does not arise from a single cause. Asan Medical Center explains that UV exposure stimulates the cells that produce melanin, worsening melasma. Reducing sun exposure may make it fade, but not every spot disappears completely. Therefore, the fact that melasma remains despite sunscreen use does not by itself mean that the product was ineffective or that skincare was poorly managed. [3]

Instead, look back over the day after applying sunscreen in the morning. Whether you reapplied during a lunchtime walk or outdoor exercise, protected not only your face but also your ears and neck, and made use of hats or shade can change your actual care plan. The Korea Disease Control and Prevention Agency likewise recommends clothing that covers the skin, hats, and sunglasses along with sunscreen. Cool weather does not mean there is no UV exposure. On days spent outdoors for extended periods, such as viewing autumn foliage or playing golf, it is worth taking the sunscreen out of your bag again. [9·10]

People with melasma may also want to consider the color of their product. The American Academy of Dermatology notes that visible light, in addition to UV light, can worsen melasma and presents tinted sunscreens containing iron oxides as an option. However, one should not expect the same protective effect simply because a product is labeled “tone-up.” Its UV protection performance and ingredients should be checked together. [10]

If I want to get rid of it quickly, should I start with a laser?

Lasers are a genuine treatment option used in pigmentation management. However, the approach that “it is brown, so it should be treated with the same laser” is not appropriate. Severance explains that melasma treatment outcomes vary according to skin type and the depth of the pigmentation, among other factors, and that recovery time is needed between treatments. The American Academy of Dermatology also recommends making UV protection and topical medication the foundation of melasma treatment, adding procedures when necessary. [4·5]

With melasma in particular, becoming temporarily lighter is not the same as not becoming darker again. Whether to repeat laser treatments alone, begin with a topical medication, or allow irritated skin to rest should be decided after diagnosis. Patients should also be informed about reactions after treatment, such as redness, scabbing, or temporarily darkened pigmentation. If an important event or trip is coming up, it is better to discuss not only the treatment date but also recovery and sun-exposure plans. [4·8]

Topical medications should not be mixed and used arbitrarily like cosmetics, either. Ingredients such as hydroquinone or azelaic acid may be considered for melasma, but the appropriate type and duration of use for one’s skin are necessary. Avoid hurriedly purchasing “secret” creams with unclear ingredient lists or overseas whitening products. The US FDA warns about the risks of mercury-containing products and unapproved over-the-counter hydroquinone skin-lightening products, distinguishing them from hydroquinone products prescribed by medical professionals. In Korea, choices should be made according to domestic approvals and the guidance of a doctor or pharmacist. [3·11]

Can these spots also be removed as a cosmetic procedure?

A spot that enlarges quickly in one area, changes in color or shape, looks distinctly different from other spots, or bleeds or itches should be examined first. The American Academy of Dermatology identifies such changes as signs that skin cancer should be evaluated. If a suspicious lesion is first lightened with a whitening product or laser, an opportunity for accurate assessment may be lost. Not every brown spot is dangerous, but changing spots should not automatically be dismissed as ordinary blemishes. [8·12]

Dr. Kang Jung-ha’s recommendations

In daily life, start with these three steps. First, before going outside, use a broad-spectrum product that protects against both UVA and UVB, and reapply about every two hours outdoors. Look for SPF 30 or higher as a baseline, and reapply according to the product instructions if you sweat heavily or come into contact with water. Second, use a wide-brimmed hat and shade together for golf, hiking, and travel. Third, do not continue using cosmetics that sting or burn, and reduce exfoliation that irritates the skin. [9·10]

In consultation, establish the treatment sequence around two priorities. If the condition is confirmed as melasma, discuss whether topical medications such as hydroquinone or azelaic acid are appropriate while maintaining UV protection. Lasers should be considered selectively after assessing the response to medication and daily care, the type of pigmentation, and the condition of the skin. Treatment aimed at individual lesions, such as lentigines, should be distinguished from a melasma treatment plan, and potential side effects—including redness, scabbing, and pigment changes—as well as the recovery period should be reviewed first. The first appointment to book is not a package involving numerous sessions, but a consultation to determine what your pigmentation actually is. [3·4·8]

This article provides general health information. Individual diagnosis and treatment should be determined through a medical consultation.

Interesting skin stories for healthier skin

Drawing on 16 years of experience running Seolleim Clinic Gangnam and expertise in dermatological procedures, we present accessible, friendly stories about skincare methods that can be practiced in daily life, as well as interesting dermatology topics involving celebrities, stars, and television programs. Through professional knowledge and experience, we aim to help your skin shine with greater health and beauty. We hope this series broadens your understanding of skin and helps you discover ways to care for yourself.

Dr. Kang Jung-ha, Director (Seolleim Clinic Gangnam)