{"id":8631,"date":"2025-06-08T18:32:44","date_gmt":"2025-06-08T22:32:44","guid":{"rendered":"https:\/\/pressbooks.bccampus.ca\/pathology\/?post_type=chapter&#038;p=8631"},"modified":"2025-08-23T23:53:47","modified_gmt":"2025-08-24T03:53:47","slug":"vitiligo","status":"publish","type":"chapter","link":"https:\/\/pressbooks.bccampus.ca\/pathology\/chapter\/vitiligo\/","title":{"raw":"Vitiligo","rendered":"Vitiligo"},"content":{"raw":"<div class=\"textbox textbox--learning-objectives\"><header class=\"textbox__header\">\r\n<p class=\"textbox__title\">Learning Objectives<\/p>\r\n\r\n<\/header>\r\n<div class=\"textbox__content\">\r\n\r\nBy the end of this section, you will be able to:\r\n<ul>\r\n \t<li>Describe the basics of skin anatomy and the key players in the melanin production pathway.<\/li>\r\n \t<li>Distinguish between segmental and non-segmental vitiligo based on mechanism and incidence rate.<\/li>\r\n \t<li>Describe the autoimmune aspect of vitiligo development and action.<\/li>\r\n \t<li>Explain vitiligo diagnoses, treatment options and their mechanisms of action.<\/li>\r\n<\/ul>\r\n<\/div>\r\n<\/div>\r\n<h2>Introduction and Classification<\/h2>\r\n<div>Vitiligo is a skin condition defined by localized patches of depigmentation of the skin, irises, and hair. Although it is more noticeable in individuals with darker skin, it can occur in people of all races and ethnicities, with a global incidence rate between 0.5-1.5%. This disease is comprised of two main types: non-segmental and segmental vitiligo. Non-segmental vitiligo is more common, affecting ~0.5% of the Canadian population and makes up ~85% of all vitiligo cases. In this sub-type, hypopigmentation may be observed across the body, most often affecting the hands, forearms, neck, scalp, feet, and face. Segmental vitiligo occurs mostly in children, asymmetrically along single spinal nerves. In both cases, depigmented areas vary greatly in size and can expand or merge over time. Since segmental vitiligo does not have an autoimmune component, it will not be the focus of this chapter.<\/div>\r\n<div>\r\n\r\n[caption id=\"attachment_8636\" align=\"aligncenter\" width=\"813\"]<img class=\"size-full wp-image-8636\" src=\"https:\/\/pressbooks.bccampus.ca\/pathology\/wp-content\/uploads\/sites\/1260\/2025\/06\/hands-.png\" alt=\"Example non-segmental vitiligo in a patient hands\" width=\"813\" height=\"496\" \/> Example non-segmental vitiligo in a patient hands \u00a9 Tor Langeland is licensed under a\u00a0<a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\" rel=\"license\">CC BY-NC (Attribution NonCommercial)<\/a> license[\/caption]\r\n\r\n<\/div>\r\n<h2>Skin Anatomy<\/h2>\r\n<div>The main site of vitiligo is the skin, which can be divided into three layers. The innermost layer is hypodermis, which contains fat and connective tissue. The middle layer is the dermis, and contains hair follicles, nerves, and blood vessels. The outermost layer is the epidermis, which contains many cell types, and is the site of vitiligo development. The main cell type in the epidermis is the keratinocytes, which contain and produce protein keratin. Keratin is a strong fibrous protein, which protects skin cells from being destroyed by rough materials.<\/div>\r\n<div>\r\n\r\n[caption id=\"attachment_8637\" align=\"aligncenter\" width=\"834\"]<img class=\"size-full wp-image-8637\" src=\"https:\/\/pressbooks.bccampus.ca\/pathology\/wp-content\/uploads\/sites\/1260\/2025\/06\/skin.png\" alt=\"Diagram of the skin and its layers.\" width=\"834\" height=\"542\" \/> Diagram of the skin and its layers. \u00a9 Cancer Research UK is licensed under a\u00a0<a href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/4.0\/\" rel=\"license\">CC BY-SA (Attribution ShareAlike)<\/a>\u00a0license[\/caption]\r\n\r\n<\/div>\r\n<h2>Melanin Production and Metabolism<\/h2>\r\n<div>Keratinocytes develop at the deepest layer of the epidermis, the stratum basale, which is a single layer of stem cells which continuously divide. The stratum basale also contains melanocytes, which secrete the pigment melanin. Different subtypes of melanin protein exist, and the rate of metabolism and relative quantities of melanin ultimately dictate a person's skin color. When keratinocytes are exposed to sun, they send a chemical signal to the melanocytes which are then stimulated to produce more melanin. Through small sacs called melanosomes, maturing keratinocytes obtain and metabolize melanin into their cells. Melanin is able to act as a natural sunscreen, because its protein structure scatters and disrupts UV light, which prevents DNA damage to skin cells, which can cause skin cancer.<\/div>\r\n<div>\r\n\r\n[caption id=\"attachment_8638\" align=\"aligncenter\" width=\"1000\"]<img class=\"size-full wp-image-8638\" src=\"https:\/\/pressbooks.bccampus.ca\/pathology\/wp-content\/uploads\/sites\/1260\/2025\/06\/melanin-production-pathway-.png\" alt=\"In depth view of melanin production pathway.\" width=\"1000\" height=\"686\" \/> In depth view of melanin production pathway. \u00a9 Synman et al. is licensed under a\u00a0<a href=\"https:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0\/\" rel=\"license\">CC BY-NC-ND (Attribution NonCommercial NoDerivatives)<\/a>\u00a0license[\/caption]\r\n\r\n<\/div>\r\n<h2>Vitiligo Pathogenesis<\/h2>\r\n<div>Vitiligo pathogenesis results in the destruction of melanocytes. In the case of non-segmental vitiligo development, autoimmune attack is responsible for the destruction. A recent meta-analysis indicated that there is a genetic component, as some [pb_glossary id=\"8909\"]human leukocyte antigen[\/pb_glossary] (HLA) genes are associated with increased risk of non-segmental vitiligo, including HLA-A02, HLA-A33, and HLA-Aw31. In addition, people with vitiligo are at greater risk of autoimmune comorbidities. Although the autoimmune trigger remains unclear, it has been proposed that melanocyte proteins can act as [pb_glossary id=\"8923\"]autoantigens [\/pb_glossary] in vitiligo disease. Melanocyte-specific antibodies may induce apoptosis of melanocytes in the affected areas. Inflammation may trigger an influx of immune cells, such as Th17 cells (a subset of [pb_glossary id=\"8499\"]helper T cells[\/pb_glossary]), and [pb_glossary id=\"8500\"]cytotoxic T cells[\/pb_glossary]. Simultaneously, [pb_glossary id=\"8507\"]regulatory T (Treg) cells[\/pb_glossary] are downregulated, and as the immune response persists, melanocytes are continuously damaged. Furthermore, the activation of [pb_glossary id=\"8924\"]inflammasomes [\/pb_glossary] and intracellular protein complexes aid in the overproduction of proinflammatory [pb_glossary id=\"4775\"]cytokines[\/pb_glossary]\u00a0such as IL-1\u03b2 and IL-18, which elevates the destruction of melanocytes.\r\n<h2>Diagnosis and Treatment<\/h2>\r\n<\/div>\r\nVitiligo diagnosis is primarily made by visual inspection of the skin. Observations of localized hypopigmented skin patches can often be made by the naked eye, although tools such as a Woods lamp can be useful for further inspection. A Woods lamp shines long wave ultraviolet light, and in the absence of other light, it makes patches and boarders of vitiligo lesions exceptionally clear. Blood tests are also a useful tool in vitiligo diagnosis, particularly in ruling out the possibility of other skin conditions causing depigmentation. Blood examination would test for the presence of antibodies and vitamin deficiencies which could cause skin abnormalities not associated with vitiligo diagnosis. <span style=\"text-align: initial;font-size: 1em\">It is worth noting that vitiligo is often underdiagnosed or misdiagnosed depending on people's ethnicity or skin tone. <\/span><span style=\"font-size: 1em;text-align: initial\">People with darker skin may be hastily diagnosed with vitiligo despite the possibility of other skin depigmentation mechanisms. In contrast, people with lighter skin are often undiagnosed or do not seek medical attention when patches are found.<\/span>\r\n\r\nVitiligo treatment has historically depended on the size of hypopigmented areas. If the areas are small, cosmetic coverup or topical immune suppressants may be applied. Topical immunosuppressants, such as the promising new drug Opzerula, act by altering the immune system in the skin only, opposed to the entire immune system. Such drugs can reduce or prevent the activity of T cells or cytokines, resulting in a reduction of inflammation and risk of melanocyte breakdown.\r\n\r\nIf the areas are large, systemic immune suppression, skin bleaching, or skin grafts may be used. Systemic immune suppressant drugs include corticosteroids such as Prednisone, Betamethasone, and Dexamethasone. Such drugs can reduce the activity of the entire immune system, resulting in the slowing or complete prevention of melanocyte destruction. However, if such drugs are used, close monitoring from a medical professional is necessary, as increased risk of dangerous infection and other complications become prevalent.\r\n<div>\r\n\r\n[caption id=\"attachment_8639\" align=\"aligncenter\" width=\"533\"]<img class=\"size-full wp-image-8639\" src=\"https:\/\/pressbooks.bccampus.ca\/pathology\/wp-content\/uploads\/sites\/1260\/2025\/06\/MJ.png\" alt=\"Michael Jackson, undoubtably the most famous person with vitiligo. Jackson used both skin grafts and cosmetic makeup to aid his condition.\" width=\"533\" height=\"711\" \/> Michael Jackson, undoubtably the most famous person with vitiligo. Jackson used both skin grafts and cosmetic makeup to aid his condition. \u00a9 Georges Biard is licensed under a\u00a0<a href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/4.0\/\" rel=\"license\">CC BY-SA (Attribution ShareAlike)<\/a> license[\/caption]\r\n\r\n<\/div>\r\nIn all cases of vitiligo, it is crucial for patients to wear sunscreen, as depigmented skin lacking melanin is especially vulnerable to burns and UV radiation, which may result in skin cancer (<a href=\"https:\/\/pressbooks.bccampus.ca\/pathology\/chapter\/chapter-summary-credits-self-tests\/\">Melanoma<\/a>). Today, there is an increasing movement towards embracing the cosmetic effects of vitiligo and redefining conventional beauty standards. Because vitiligo does not inherently impose health risks, other than increased risk of UV damage, many individuals have opted out of therapeutic regimes.\r\n<div>\r\n\r\n[caption id=\"attachment_8640\" align=\"aligncenter\" width=\"527\"]<img class=\"size-full wp-image-8640\" src=\"https:\/\/pressbooks.bccampus.ca\/pathology\/wp-content\/uploads\/sites\/1260\/2025\/06\/winnie-.png\" alt=\"Winnie Harlow is a world famous fashion model with vitiligo. She is a spokesperson in the ongoing movement of vitiligo representation and awareness.\" width=\"527\" height=\"626\" \/> Winnie Harlow is a world famous fashion model with vitiligo. She is a spokesperson in the ongoing movement of vitiligo representation and awareness. \u00a9 Georges Biard is licensed under a\u00a0<a href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/4.0\/\" rel=\"license\">CC BY-SA (Attribution ShareAlike)<\/a>\u00a0license[\/caption]\r\n\r\n<\/div>\r\n<h1>Review Questions<\/h1>\r\n[h5p id=\"423\"]","rendered":"<div class=\"textbox textbox--learning-objectives\">\n<header class=\"textbox__header\">\n<p class=\"textbox__title\">Learning Objectives<\/p>\n<\/header>\n<div class=\"textbox__content\">\n<p>By the end of this section, you will be able to:<\/p>\n<ul>\n<li>Describe the basics of skin anatomy and the key players in the melanin production pathway.<\/li>\n<li>Distinguish between segmental and non-segmental vitiligo based on mechanism and incidence rate.<\/li>\n<li>Describe the autoimmune aspect of vitiligo development and action.<\/li>\n<li>Explain vitiligo diagnoses, treatment options and their mechanisms of action.<\/li>\n<\/ul>\n<\/div>\n<\/div>\n<h2>Introduction and Classification<\/h2>\n<div>Vitiligo is a skin condition defined by localized patches of depigmentation of the skin, irises, and hair. Although it is more noticeable in individuals with darker skin, it can occur in people of all races and ethnicities, with a global incidence rate between 0.5-1.5%. This disease is comprised of two main types: non-segmental and segmental vitiligo. Non-segmental vitiligo is more common, affecting ~0.5% of the Canadian population and makes up ~85% of all vitiligo cases. In this sub-type, hypopigmentation may be observed across the body, most often affecting the hands, forearms, neck, scalp, feet, and face. Segmental vitiligo occurs mostly in children, asymmetrically along single spinal nerves. In both cases, depigmented areas vary greatly in size and can expand or merge over time. Since segmental vitiligo does not have an autoimmune component, it will not be the focus of this chapter.<\/div>\n<div>\n<figure id=\"attachment_8636\" aria-describedby=\"caption-attachment-8636\" style=\"width: 813px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-8636\" src=\"https:\/\/pressbooks.bccampus.ca\/pathology\/wp-content\/uploads\/sites\/1260\/2025\/06\/hands-.png\" alt=\"Example non-segmental vitiligo in a patient hands\" width=\"813\" height=\"496\" srcset=\"https:\/\/pressbooks.bccampus.ca\/pathology\/wp-content\/uploads\/sites\/1260\/2025\/06\/hands-.png 813w, https:\/\/pressbooks.bccampus.ca\/pathology\/wp-content\/uploads\/sites\/1260\/2025\/06\/hands--300x183.png 300w, https:\/\/pressbooks.bccampus.ca\/pathology\/wp-content\/uploads\/sites\/1260\/2025\/06\/hands--768x469.png 768w, https:\/\/pressbooks.bccampus.ca\/pathology\/wp-content\/uploads\/sites\/1260\/2025\/06\/hands--65x40.png 65w, https:\/\/pressbooks.bccampus.ca\/pathology\/wp-content\/uploads\/sites\/1260\/2025\/06\/hands--225x137.png 225w, https:\/\/pressbooks.bccampus.ca\/pathology\/wp-content\/uploads\/sites\/1260\/2025\/06\/hands--350x214.png 350w\" sizes=\"auto, (max-width: 813px) 100vw, 813px\" \/><figcaption id=\"caption-attachment-8636\" class=\"wp-caption-text\">Example non-segmental vitiligo in a patient hands \u00a9 Tor Langeland is licensed under a\u00a0<a href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\" rel=\"license\">CC BY-NC (Attribution NonCommercial)<\/a> license<\/figcaption><\/figure>\n<\/div>\n<h2>Skin Anatomy<\/h2>\n<div>The main site of vitiligo is the skin, which can be divided into three layers. The innermost layer is hypodermis, which contains fat and connective tissue. The middle layer is the dermis, and contains hair follicles, nerves, and blood vessels. The outermost layer is the epidermis, which contains many cell types, and is the site of vitiligo development. The main cell type in the epidermis is the keratinocytes, which contain and produce protein keratin. Keratin is a strong fibrous protein, which protects skin cells from being destroyed by rough materials.<\/div>\n<div>\n<figure id=\"attachment_8637\" aria-describedby=\"caption-attachment-8637\" style=\"width: 834px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-8637\" src=\"https:\/\/pressbooks.bccampus.ca\/pathology\/wp-content\/uploads\/sites\/1260\/2025\/06\/skin.png\" alt=\"Diagram of the skin and its layers.\" width=\"834\" height=\"542\" srcset=\"https:\/\/pressbooks.bccampus.ca\/pathology\/wp-content\/uploads\/sites\/1260\/2025\/06\/skin.png 834w, https:\/\/pressbooks.bccampus.ca\/pathology\/wp-content\/uploads\/sites\/1260\/2025\/06\/skin-300x195.png 300w, https:\/\/pressbooks.bccampus.ca\/pathology\/wp-content\/uploads\/sites\/1260\/2025\/06\/skin-768x499.png 768w, https:\/\/pressbooks.bccampus.ca\/pathology\/wp-content\/uploads\/sites\/1260\/2025\/06\/skin-65x42.png 65w, https:\/\/pressbooks.bccampus.ca\/pathology\/wp-content\/uploads\/sites\/1260\/2025\/06\/skin-225x146.png 225w, https:\/\/pressbooks.bccampus.ca\/pathology\/wp-content\/uploads\/sites\/1260\/2025\/06\/skin-350x227.png 350w\" sizes=\"auto, (max-width: 834px) 100vw, 834px\" \/><figcaption id=\"caption-attachment-8637\" class=\"wp-caption-text\">Diagram of the skin and its layers. \u00a9 Cancer Research UK is licensed under a\u00a0<a href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/4.0\/\" rel=\"license\">CC BY-SA (Attribution ShareAlike)<\/a>\u00a0license<\/figcaption><\/figure>\n<\/div>\n<h2>Melanin Production and Metabolism<\/h2>\n<div>Keratinocytes develop at the deepest layer of the epidermis, the stratum basale, which is a single layer of stem cells which continuously divide. The stratum basale also contains melanocytes, which secrete the pigment melanin. Different subtypes of melanin protein exist, and the rate of metabolism and relative quantities of melanin ultimately dictate a person&#8217;s skin color. When keratinocytes are exposed to sun, they send a chemical signal to the melanocytes which are then stimulated to produce more melanin. Through small sacs called melanosomes, maturing keratinocytes obtain and metabolize melanin into their cells. Melanin is able to act as a natural sunscreen, because its protein structure scatters and disrupts UV light, which prevents DNA damage to skin cells, which can cause skin cancer.<\/div>\n<div>\n<figure id=\"attachment_8638\" aria-describedby=\"caption-attachment-8638\" style=\"width: 1000px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-8638\" src=\"https:\/\/pressbooks.bccampus.ca\/pathology\/wp-content\/uploads\/sites\/1260\/2025\/06\/melanin-production-pathway-.png\" alt=\"In depth view of melanin production pathway.\" width=\"1000\" height=\"686\" srcset=\"https:\/\/pressbooks.bccampus.ca\/pathology\/wp-content\/uploads\/sites\/1260\/2025\/06\/melanin-production-pathway-.png 1000w, https:\/\/pressbooks.bccampus.ca\/pathology\/wp-content\/uploads\/sites\/1260\/2025\/06\/melanin-production-pathway--300x206.png 300w, https:\/\/pressbooks.bccampus.ca\/pathology\/wp-content\/uploads\/sites\/1260\/2025\/06\/melanin-production-pathway--768x527.png 768w, https:\/\/pressbooks.bccampus.ca\/pathology\/wp-content\/uploads\/sites\/1260\/2025\/06\/melanin-production-pathway--65x45.png 65w, https:\/\/pressbooks.bccampus.ca\/pathology\/wp-content\/uploads\/sites\/1260\/2025\/06\/melanin-production-pathway--225x154.png 225w, https:\/\/pressbooks.bccampus.ca\/pathology\/wp-content\/uploads\/sites\/1260\/2025\/06\/melanin-production-pathway--350x240.png 350w\" sizes=\"auto, (max-width: 1000px) 100vw, 1000px\" \/><figcaption id=\"caption-attachment-8638\" class=\"wp-caption-text\">In depth view of melanin production pathway. \u00a9 Synman et al. is licensed under a\u00a0<a href=\"https:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0\/\" rel=\"license\">CC BY-NC-ND (Attribution NonCommercial NoDerivatives)<\/a>\u00a0license<\/figcaption><\/figure>\n<\/div>\n<h2>Vitiligo Pathogenesis<\/h2>\n<div>Vitiligo pathogenesis results in the destruction of melanocytes. In the case of non-segmental vitiligo development, autoimmune attack is responsible for the destruction. A recent meta-analysis indicated that there is a genetic component, as some <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_8631_8909\">human leukocyte antigen<\/a> (HLA) genes are associated with increased risk of non-segmental vitiligo, including HLA-A02, HLA-A33, and HLA-Aw31. In addition, people with vitiligo are at greater risk of autoimmune comorbidities. Although the autoimmune trigger remains unclear, it has been proposed that melanocyte proteins can act as <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_8631_8923\">autoantigens <\/a> in vitiligo disease. Melanocyte-specific antibodies may induce apoptosis of melanocytes in the affected areas. Inflammation may trigger an influx of immune cells, such as Th17 cells (a subset of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_8631_8499\">helper T cells<\/a>), and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_8631_8500\">cytotoxic T cells<\/a>. Simultaneously, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_8631_8507\">regulatory T (Treg) cells<\/a> are downregulated, and as the immune response persists, melanocytes are continuously damaged. Furthermore, the activation of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_8631_8924\">inflammasomes <\/a> and intracellular protein complexes aid in the overproduction of proinflammatory <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_8631_4775\">cytokines<\/a>\u00a0such as IL-1\u03b2 and IL-18, which elevates the destruction of melanocytes.<\/p>\n<h2>Diagnosis and Treatment<\/h2>\n<\/div>\n<p>Vitiligo diagnosis is primarily made by visual inspection of the skin. Observations of localized hypopigmented skin patches can often be made by the naked eye, although tools such as a Woods lamp can be useful for further inspection. A Woods lamp shines long wave ultraviolet light, and in the absence of other light, it makes patches and boarders of vitiligo lesions exceptionally clear. Blood tests are also a useful tool in vitiligo diagnosis, particularly in ruling out the possibility of other skin conditions causing depigmentation. Blood examination would test for the presence of antibodies and vitamin deficiencies which could cause skin abnormalities not associated with vitiligo diagnosis. <span style=\"text-align: initial;font-size: 1em\">It is worth noting that vitiligo is often underdiagnosed or misdiagnosed depending on people&#8217;s ethnicity or skin tone. <\/span><span style=\"font-size: 1em;text-align: initial\">People with darker skin may be hastily diagnosed with vitiligo despite the possibility of other skin depigmentation mechanisms. In contrast, people with lighter skin are often undiagnosed or do not seek medical attention when patches are found.<\/span><\/p>\n<p>Vitiligo treatment has historically depended on the size of hypopigmented areas. If the areas are small, cosmetic coverup or topical immune suppressants may be applied. Topical immunosuppressants, such as the promising new drug Opzerula, act by altering the immune system in the skin only, opposed to the entire immune system. Such drugs can reduce or prevent the activity of T cells or cytokines, resulting in a reduction of inflammation and risk of melanocyte breakdown.<\/p>\n<p>If the areas are large, systemic immune suppression, skin bleaching, or skin grafts may be used. Systemic immune suppressant drugs include corticosteroids such as Prednisone, Betamethasone, and Dexamethasone. Such drugs can reduce the activity of the entire immune system, resulting in the slowing or complete prevention of melanocyte destruction. However, if such drugs are used, close monitoring from a medical professional is necessary, as increased risk of dangerous infection and other complications become prevalent.<\/p>\n<div>\n<figure id=\"attachment_8639\" aria-describedby=\"caption-attachment-8639\" style=\"width: 533px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-8639\" src=\"https:\/\/pressbooks.bccampus.ca\/pathology\/wp-content\/uploads\/sites\/1260\/2025\/06\/MJ.png\" alt=\"Michael Jackson, undoubtably the most famous person with vitiligo. Jackson used both skin grafts and cosmetic makeup to aid his condition.\" width=\"533\" height=\"711\" srcset=\"https:\/\/pressbooks.bccampus.ca\/pathology\/wp-content\/uploads\/sites\/1260\/2025\/06\/MJ.png 533w, https:\/\/pressbooks.bccampus.ca\/pathology\/wp-content\/uploads\/sites\/1260\/2025\/06\/MJ-225x300.png 225w, https:\/\/pressbooks.bccampus.ca\/pathology\/wp-content\/uploads\/sites\/1260\/2025\/06\/MJ-65x87.png 65w, https:\/\/pressbooks.bccampus.ca\/pathology\/wp-content\/uploads\/sites\/1260\/2025\/06\/MJ-350x467.png 350w\" sizes=\"auto, (max-width: 533px) 100vw, 533px\" \/><figcaption id=\"caption-attachment-8639\" class=\"wp-caption-text\">Michael Jackson, undoubtably the most famous person with vitiligo. Jackson used both skin grafts and cosmetic makeup to aid his condition. \u00a9 Georges Biard is licensed under a\u00a0<a href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/4.0\/\" rel=\"license\">CC BY-SA (Attribution ShareAlike)<\/a> license<\/figcaption><\/figure>\n<\/div>\n<p>In all cases of vitiligo, it is crucial for patients to wear sunscreen, as depigmented skin lacking melanin is especially vulnerable to burns and UV radiation, which may result in skin cancer (<a href=\"https:\/\/pressbooks.bccampus.ca\/pathology\/chapter\/chapter-summary-credits-self-tests\/\">Melanoma<\/a>). Today, there is an increasing movement towards embracing the cosmetic effects of vitiligo and redefining conventional beauty standards. Because vitiligo does not inherently impose health risks, other than increased risk of UV damage, many individuals have opted out of therapeutic regimes.<\/p>\n<div>\n<figure id=\"attachment_8640\" aria-describedby=\"caption-attachment-8640\" style=\"width: 527px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-8640\" src=\"https:\/\/pressbooks.bccampus.ca\/pathology\/wp-content\/uploads\/sites\/1260\/2025\/06\/winnie-.png\" alt=\"Winnie Harlow is a world famous fashion model with vitiligo. She is a spokesperson in the ongoing movement of vitiligo representation and awareness.\" width=\"527\" height=\"626\" srcset=\"https:\/\/pressbooks.bccampus.ca\/pathology\/wp-content\/uploads\/sites\/1260\/2025\/06\/winnie-.png 527w, https:\/\/pressbooks.bccampus.ca\/pathology\/wp-content\/uploads\/sites\/1260\/2025\/06\/winnie--253x300.png 253w, https:\/\/pressbooks.bccampus.ca\/pathology\/wp-content\/uploads\/sites\/1260\/2025\/06\/winnie--65x77.png 65w, https:\/\/pressbooks.bccampus.ca\/pathology\/wp-content\/uploads\/sites\/1260\/2025\/06\/winnie--225x267.png 225w, https:\/\/pressbooks.bccampus.ca\/pathology\/wp-content\/uploads\/sites\/1260\/2025\/06\/winnie--350x416.png 350w\" sizes=\"auto, (max-width: 527px) 100vw, 527px\" \/><figcaption id=\"caption-attachment-8640\" class=\"wp-caption-text\">Winnie Harlow is a world famous fashion model with vitiligo. She is a spokesperson in the ongoing movement of vitiligo representation and awareness. \u00a9 Georges Biard is licensed under a\u00a0<a href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/4.0\/\" rel=\"license\">CC BY-SA (Attribution ShareAlike)<\/a>\u00a0license<\/figcaption><\/figure>\n<\/div>\n<h1>Review Questions<\/h1>\n<div id=\"h5p-423\">\n<div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-423\" class=\"h5p-iframe\" data-content-id=\"423\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"Vitiligo\"><\/iframe><\/div>\n<\/div>\n<div class=\"media-attributions clear\" prefix:cc=\"http:\/\/creativecommons.org\/ns#\" prefix:dc=\"http:\/\/purl.org\/dc\/terms\/\"><h2>Media Attributions<\/h2><ul><li about=\"https:\/\/sml.snl.no\/vitiligo \"><a rel=\"cc:attributionURL\" href=\"https:\/\/sml.snl.no\/vitiligo \" property=\"dc:title\">Example non-segmental vitiligo in a patient hands<\/a>  &copy;  Tor Langeland    is licensed under a  <a rel=\"license\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC (Attribution NonCommercial)<\/a> license<\/li><li about=\"https:\/\/commons.wikimedia.org\/wiki\/File:Diagram_showing_the_structure_of_the_skin_CRUK_371.svg\"><a rel=\"cc:attributionURL\" href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Diagram_showing_the_structure_of_the_skin_CRUK_371.svg\" property=\"dc:title\">Diagram of the skin and its layers.<\/a>  &copy;  Cancer Research UK    is licensed under a  <a rel=\"license\" href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/4.0\/\">CC BY-SA (Attribution ShareAlike)<\/a> license<\/li><li about=\"https:\/\/onlinelibrary.wiley.com\/doi\/10.1111\/pcmr.13165\"><a rel=\"cc:attributionURL\" href=\"https:\/\/onlinelibrary.wiley.com\/doi\/10.1111\/pcmr.13165\" property=\"dc:title\">In depth view of melanin production pathway.<\/a>  &copy;  Synman et al.    is licensed under a  <a rel=\"license\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0\/\">CC BY-NC-ND (Attribution NonCommercial NoDerivatives)<\/a> license<\/li><li about=\"https:\/\/commons.wikimedia.org\/wiki\/File:Michael_Jackson_Cannescropped.jpg \"><a rel=\"cc:attributionURL\" href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Michael_Jackson_Cannescropped.jpg \" property=\"dc:title\">Michael Jackson, undoubtably the most famous person with vitiligo. Jackson used both skin grafts and cosmetic makeup to aid his condition.<\/a>  &copy;  Georges Biard    is licensed under a  <a rel=\"license\" href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/4.0\/\">CC BY-SA (Attribution ShareAlike)<\/a> license<\/li><li about=\"https:\/\/commons.wikimedia.org\/wiki\/File:Winnie_Harlow_Cannes_2017.jpg \"><a rel=\"cc:attributionURL\" href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Winnie_Harlow_Cannes_2017.jpg \" property=\"dc:title\">Winnie Harlow is a world famous fashion model with vitiligo. She is a spokesperson in the ongoing movement of vitiligo representation and awareness.<\/a>  &copy;  Georges Biard    is licensed under a  <a rel=\"license\" href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/4.0\/\">CC BY-SA (Attribution ShareAlike)<\/a> license<\/li><\/ul><\/div><div class=\"glossary\"><span class=\"screen-reader-text\" id=\"definition\">definition<\/span><template id=\"term_8631_8909\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_8631_8909\"><div tabindex=\"-1\"><p>genes part of the major histocompatibility complex<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_8631_8923\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_8631_8923\"><div tabindex=\"-1\"><p>normal components of an individual's own body that are mistakenly targeted by the immune system<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_8631_8499\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_8631_8499\"><div tabindex=\"-1\"><p>cell of the adaptive immune system that binds APCs via MHC II molecules and stimulates B cells or secretes cytokines to initiate the immune response<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_8631_8500\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_8631_8500\"><div tabindex=\"-1\"><p>adaptive immune cell that directly kills infected cells via perforin and granzymes, and releases cytokines to enhance the immune response<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_8631_8507\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_8631_8507\"><div tabindex=\"-1\"><p>specialized lymphocyte that suppresses local inflammation and inhibits the secretion of cytokines, antibodies, and other stimulatory immune factors; involved in immune tolerance<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_8631_8924\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_8631_8924\"><div tabindex=\"-1\"><p>multiprotein complexes that activate inflammatory responses <\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_8631_4775\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_8631_4775\"><div tabindex=\"-1\"><p>small proteins released by cells; allow for communication between the cells involved in the same type of immune response\/reaction<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><\/div>","protected":false},"author":2432,"menu_order":10,"template":"","meta":{"pb_show_title":"on","pb_short_title":"Vitiligo","pb_subtitle":"Vitiligo","pb_authors":["dylanmann","morganalford"],"pb_section_license":""},"chapter-type":[],"contributor":[538,535],"license":[58],"class_list":["post-8631","chapter","type-chapter","status-publish","hentry","contributor-dylanmann","contributor-morganalford","license-all-rights-reserved"],"part":8316,"_links":{"self":[{"href":"https:\/\/pressbooks.bccampus.ca\/pathology\/wp-json\/pressbooks\/v2\/chapters\/8631","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/pressbooks.bccampus.ca\/pathology\/wp-json\/pressbooks\/v2\/chapters"}],"about":[{"href":"https:\/\/pressbooks.bccampus.ca\/pathology\/wp-json\/wp\/v2\/types\/chapter"}],"author":[{"embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/pathology\/wp-json\/wp\/v2\/users\/2432"}],"version-history":[{"count":15,"href":"https:\/\/pressbooks.bccampus.ca\/pathology\/wp-json\/pressbooks\/v2\/chapters\/8631\/revisions"}],"predecessor-version":[{"id":9521,"href":"https:\/\/pressbooks.bccampus.ca\/pathology\/wp-json\/pressbooks\/v2\/chapters\/8631\/revisions\/9521"}],"part":[{"href":"https:\/\/pressbooks.bccampus.ca\/pathology\/wp-json\/pressbooks\/v2\/parts\/8316"}],"metadata":[{"href":"https:\/\/pressbooks.bccampus.ca\/pathology\/wp-json\/pressbooks\/v2\/chapters\/8631\/metadata\/"}],"wp:attachment":[{"href":"https:\/\/pressbooks.bccampus.ca\/pathology\/wp-json\/wp\/v2\/media?parent=8631"}],"wp:term":[{"taxonomy":"chapter-type","embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/pathology\/wp-json\/pressbooks\/v2\/chapter-type?post=8631"},{"taxonomy":"contributor","embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/pathology\/wp-json\/wp\/v2\/contributor?post=8631"},{"taxonomy":"license","embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/pathology\/wp-json\/wp\/v2\/license?post=8631"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}