Why is melasma so stubborn—and what can you really do about it?

Melasma remains one of the most challenging pigmentary disorders because it is chronic and driven by multiple pathways. Beyond UV exposure, visible light (blue light), hormonal influences, inflammation, pollution, and genetic predisposition all play a role in stimulating melanocytes. 

This ongoing activation is what leads to its high recurrence rate, even after treatment. In addition, compliance with treatment is also a problem. One of the cornerstones of treatment is regular sunblock every 4-6 hours, even when indoors, and most patients find it hard to comply.

Traditionally, Kligman’s Formula—combining 4% hydroquinone, a retinoid, and a corticosteroid—has been regarded as the gold standard for melasma treatment. While effective, dermatologists generally recommend it only for short-term use under supervision due to potential side effects, including irritation, rebound pigmentation, steroid-related skin changes, and, with prolonged hydroquinone use, ochronosis.

How melasma differs from other pigmentation

Melasma differs from other types of pigmentation in both its pathophysiology and clinical behaviour. Spotty pigmentation in sun spots (solar lentigines) is primarily due to cumulative UV exposure and presents as small, well-defined lesions. Post-inflammatory hyperpigmentation, such as post-acne marks, is also spotty, occurs secondary to skin inflammation, and is typically transient.

In contrast, melasma is a chronic, relapsing pigmentary disorder characterised by larger, symmetrical patches, most commonly on the cheeks, forehead, and upper lip. It is driven by a multifactorial process involving hormonal influences, UV and visible light exposure, and ongoing skin inflammation. Because these triggers are persistent, systemic, and environmental, melasma is more prone to recurrence and is generally more challenging to treat, requiring long-term management and strict photoprotection.

The overlooked triggers for stubborn pigmentation

Most people think melasma is caused only by the sun, but it’s actually triggered by multiple factors. Beyond UV and visible light, heat can also stimulate pigmentation—especially in hot, urban environments. Hormonal changes remain a key driver, but chronic inflammation inside the skin also plays a major role. Environmental pollution has also been shown to cause skin pigmentation, and the only way to combat it is through avoidance and the application of skin antioxidants.

One important but lesser-known factor is skin glycation—a process where excess sugar binds to proteins in the skin, leading to oxidative stress and triggering pigmentation pathways. This internal “skin stress” can make melasma more persistent over time. 

Another key factor is the skin barrier. When the skin barrier is weakened or dehydrated, it becomes more reactive to everyday stressors like sunlight, pollution, and even skincare—making pigmentation harder to control. This is why modern approaches to melasma go beyond simply blocking melanin. The focus is shifting toward protecting the skin from multiple light sources, reducing internal stress like glycation and inflammation, and strengthening the skin barrier for more stable, long-term results.

Managing melasma

Managing melasma takes patience and consistency—it’s not something that can be fixed overnight, but it can be controlled with the right routine. The most important steps are: 

Protect your skin from the sun every day. Sun exposure is the biggest trigger for melasma. Use a broad-spectrum sunscreen (SPF 50 or higher) every morning, even on cloudy days, and reapply if you’re outdoors. 

Use the right skincare consistently. Look for products that help brighten skin and even out tone, but are also gentle enough to use every day. Consistency is key—stopping and starting can make pigmentation come back more easily. 

Keep your skin healthy and hydrated. When your skin barrier is strong and well-hydrated, it is less likely to become irritated—and irritation can make pigmentation worse. 

Be mindful of triggers. Heat, sunlight, and even hormonal changes can worsen melasma.

Catherine Tan is the founder of Singapore beauty brand Crystal Tomato, known for its science‑driven approach to pigmentation and skin health informed by clinical trials and dermatologist engagement.