What is the prevalence of vitiligo in different regions of the world?

Vitiligo is a skin condition that results in the appearance of white patches of varying sizes on the face and/or body. It is an autoimmune disease where the immune system mistakenly attacks the melanocytes, the skin cells responsible for producing melanin, the pigment that colors the epidermis. Vitiligo can affect both adults and children, regardless of their gender and skin color, and results from a combination of various genetic and environmental factors, such as exposure to pollution, dust mites, or the Koebner phenomenon.

The prevalence of vitiligo in the global population varies between 0.5 and 2%, with some differences across continents.

A meta-analysis, a systematic scientific method that combines the results of a series of independent studies, was conducted on this subject in 2024 and the findings were published in The Lancet. 82 studies, carried out in 189 countries worldwide with data spanning the period 1971-2020, were included. The results of these studies allowed for the creation of the map below, showing the prevalence of vitiligo by country.

Asia is a region of the world where the prevalence of vitiligo is highest, with rates fluctuating between 0.2 and 2%. This is particularly true in India, where some research suggests that up to 8.8% of the population is affected by vitiligo. This higher prevalence could be due to a greater genetic predisposition, but also to better detection, as vitiligo is well-known and studied in this country. In fact, it is the country that has conducted the most clinical studies on this subject. A high prevalence of vitiligo has also been recorded in Eastern Europe, notably in Poland, Slovakia, and Hungary.

The incidence of vitiligo varies from one region to another due to several factors, combining genetic, environmental, and methodological elements.These factors interact and influence not only the frequency of vitiligo in certain populations, but also how it is diagnosed and reported.

Genetic factors can influence the prevalence of vitiligo among different populations.

Vitiligo is a polygenic disease, meaning that multiple genes are involved in its development. Numerous studies have been conducted to elucidate the genetic factors contributing to the onset of vitiligo. Over 50 susceptibility genes have been associated with the disease, such as HLA, CTLA4, NLRP1, and TYR. It's interesting to note that the genes linked to vitiligo are not the same in all parts of the world. Thus, some are more commonly found in European populations, while others have a higher prevalence in China, Japan, or India. A few examples of these peculiarities are presented in the table below.

Variations in environmental triggers of vitiligo according to different countries.

Although genetic predisposition likely plays a key role in regional disparities in vitiligo prevalence, certain environmental factors may also come into play, including exposure to UV rays and pollution. Indeed, in very sunny countries, prolonged UV exposure can cause oxidative stress in skin cells, promoting the destruction of melanocytes in genetically predisposed individuals. A similar mechanism is observed when skin is exposed to pollution, which also generates free radicals in skin cells. This could explain a higher incidence of vitiligo in certain tropical or highly polluted regions, such as India.

A varying number of studies on vitiligo depending on the countries around the world.

The prevalence of vitiligo is also influenced by the number of studies conducted in countries. Indeed, regions of the world where dermatological research is more developed, with studies involving large groups of individuals, tend to provide more accurate figures. As mentioned earlier, India, for example, has numerous scientific publications on vitiligo, reflecting better documentation of cases. Conversely, in sub-Saharan Africa or Latin America, epidemiological studies are less frequent, making it difficult to assess the prevalence of vitiligo in these populations. This disparity in research can create a bias and a discrepancy with reality.

• SCHALLREUTER K. & al. A review of the worldwide prevalence of vitiligo in children/adolescents and adults. International Journal of Dermatology (2012).

• BORRADORI L. & al. Dermatologie et infections sexuellement transmissibles. Elsevier Masson (2017).

• EZZEDINE K. & al. Vitiligo: A Review. Dermatology (2020).

• SPRITZ R. & al. The Genetic Basis of Vitiligo. Journal of Investigative Dermatology (2021).

• KOSHI S. & al. Vitiligo: A Narrative Review. Cureus (2022).

• EZZEDINE K. & al. Estimating the burden of vitiligo: a systematic review and modelling study. The Lancet (2024).