Etiology of Melasma

Melasma is a relatively common facial hyperpigmentation disorder. It predominantly affects middle-aged women, progresses slowly, and is highly prone to recurrence—especially following sun exposure, which tends to exacerbate the condition. What, then, are the causes of melasma?

Etiology of Melasma

Melasma, also known as “liver spots” (though unrelated to hepatic disease), is a common acquired dermatosis characterized by excessive melanin deposition, typically occurring on sun-exposed areas of the face and worsening with UV exposure. It most frequently affects women of middle and young adulthood. The course is chronic, with no prominent subjective symptoms. Disease severity often exhibits seasonal variation, being milder in both summer and winter. Diagnosis may be supported by reflectance spectrophotometry: pigmentation in affected areas shows an average optical density exceeding that of unaffected facial skin by more than 20%.

Melasma is an acquired disorder of excessive melanin deposition, localized primarily to sun-exposed facial regions and aggravated by UV exposure. It is particularly prevalent among women, commonly emerging between puberty and menopause. In pregnant women, onset typically occurs during months 2–5 of gestation and gradually resolves postpartum.

However, recurrence may occur in subsequent pregnancies—a presentation termed “pregnancy-associated melasma.” In Urumqi, China, the prevalence of melasma among healthy individuals aged ≥10 years is 9.7% overall, with rates of 10.9% in males and 8.1% in females. For severe cases, photorejuvenation (e.g., intense pulsed light therapy) may effectively lighten lesions; topical depigmenting agents may also be applied locally. We hope this information proves helpful!