Global Epidemiology: Melasma

Melasma is a hyperpigmentary condition that primarily affects areas of the face that are exposed to sunlight, particularly in women and people with darker skin tones. Globally, its prevalence varies from roughly 1% in the general population to 9–50% in specific ethnic groups or those who are exposed to a lot of sunlight. According to regional data: Southeast Asia: 0.5%, Saudi Arabia: 2.9%. Arab-Americans: 13.4% to 15.5%, Latinos: 8.2–8.8%, Hispanics: 2.5 %, Iran: 16–39.5%, Morocco: up to 37 %, Paddy field workers in India and Pakistan: as much as 41–46%. These rates highlight both genetic and environmental factors and are based on population-based surveys and dermatological clinic studies. Most commonly affecting women of reproductive age and people with darker skin types who are exposed to sunlight, melasma is a common hyperpigmentation disorder with a varied global prevalence. The 8.8% of Latino women in the southwestern United States participated in a prospective telephone-based survey, and 8.2% of Latino patients participated in a follow-up dermatology practice study in New York City. Compared to clinic-based surveys, which may systematically overestimate prevalence by preferentially recruiting patients seeking treatment, these population-based studies offer more accurate estimates.