- Vitiligo is a common disorder of depigmentation that is marked by the histologic loss of epidermal melanocytes.
- Vitiligo can be classified into two main categories: vitiligo (generalized, acrofacial, mucosal, localized, generalized, universal and mixed) and segmental vitiligo.
- Vitiligo may be associated with psychosocial difficulties and with other autoimmune diseases.
- Vitiligo may be lifelong in duration, and its disease course can be difficult to predict.
- The mainstay of treatment is immunomodulation with agents such as topical corticosteroids, topical calcineurin inhibitors and narrow-band ultraviolet phototherapy; combined therapy may be the most effective therapeutic strategy.
Vitiligo is a common disorder of depigmentation marked by the histologic loss of epidermal melanocytes with minimal inflammation. It occurs in all age groups with a peak incidence in the second to third decades of life. The most recent meta-analysis found a global prevalence of approximately 0.2 to 1.8%. While the highest prevalences were seen in Africa and in female patients, reporting bias amongst women and darker skin ethnicities may be responsible for these results. Vitiligo can be distinguished from other disorders of hypopigmentation by its porcelain-white appearance; its predilection for intertriginous, acral, and periorificial areas; and the absence of any other skin changes. A simplified classification and nomenclature proposed during the 2012 Vitiligo Global Issues Consensus Conference distinguishes two major forms: “vitiligo,” an umbrella term for all non-segmental forms including generalized, acrofacial, mucosal, localized, and universal patterns; and “segmental vitiligo,” referring to lesions that follow a clinically unambiguous segmental distribution and are typically associated with rapid onset and leukotrichia (depigmentation of associated hairs). This distinction is important in determining prognosis and treatment.
Although greater than 90% of vitiligo patients have the non-segmental form, segmental vitiligo is more common in children, accounting for 15-30% of pediatric cases. In general, the clinical pattern of an individual patient is consistent throughout the course of disease. Focal lesions that are too early to distinguish can be referred to as “unclassified vitiligo” until a more definitive classification of segmental or non-segmental can be made. Rarely, a mixed form of segmental and non-segmental vitiligo called “mixed vitiligo” can be seen; this is considered to be a form of (nonsegmental) vitiligo. Vitiligo is often a clinical diagnosis and usually does not require biopsy.
Important associations include an elevated risk of other autoimmune conditions, in particular autoimmune thyroid disease, which has a median prevalence of 18.6% reported in the literature. Vitiligo can also carry a heavy psychosocial burden, with over 50% of children reporting severe impairment and with significantly increased risk for clinical depression and depressive symptoms. Regular evaluation should be performed for symptoms of autoimmune diseases and depression. It is also recommended that patients with vitiligo be screened for autoimmune thyroid disease every three years, or sooner if symptoms are present. Patients with vitiligo are more likely to have halo nevi (nevi with a rim of depigmentation), and the development of new-onset vitiligo in patients with melanoma is considered a positive prognostic factor – both being signs of active autoimmunity against melanocytes. Vogt-Koyanagi-Harada syndrome is a rare multisystem autoimmune condition that may occur following a viral illness and targets pigment in the eye, ear, meninges, skin and hair (resulting in vitiligo and poliosis). Alezzandrini syndrome is a similar though exceedingly rare condition of unilateral facial vitiligo, poliosis, retinal degeneration, and hearing loss.
The exact pathogenesis of vitiligo remains unknown; however, genetic, biochemical, viral and environmental factors have all been implicated. Risk factors for the development of vitiligo include family history and oxidative stress due to environmental exposures (i.e., to phenols and other compounds). Recipients of hematopoietic stem cell transplantation also may be at increased risk for the development of vitiligo.
The progression of depigmentation in vitiligo varies depending on the type. Segmental vitiligo progresses quickly over six months to two years and then stabilizes as it reaches the limits of the involved segment. Nonsegmental forms of vitiligo are more variable in their activity. When untreated, patients most typically experience a slow course with intermittent periods of activity and remission throughout their lifetime. Rapidly progressive forms of nonsegmental vitiligo such as universalis may rarely occur.
Most treatments for vitiligo only partially repigment the affected areas; in fact, 75% repigmentation is considered to be an excellent response to therapy. Facial areas respond best to all forms of treatment, while extremities and segmental variants can be more difficult or refractory. Immunomodulation is considered the mainstay of treatment. Phototherapy is very effective but can be inconvenient, as it requires frequent treatment sessions in order to achieve a substantial benefit. Topical corticosteroids and/or calcineurin inhibitors may also be used with variable success in localized areas of depigmentation associated with vitiligo. Relapse is common with any treatment, so setting realistic expectations and addressing the emotional impact of vitiligo is very important.