Anogenital vitiligo of childhood is an acquired disorder affecting melanocytes, resulting in depigmented, white patches of the skin involving the genitalia.

Anogenital vitiligo is often termed "figure-of-eight" disease due to a female predominance and presentation with depigmentation of the perineal and perianal skin around the vaginal and anal orifices. 

It is unclear if anogenital vitiligo of childhood is a segmental or a nonsegmental form of vitiligo. Individuals with anogenital vitiligo can have concomitant vitiligo on other sites of the body, and it may be a part of generalized vitiligo. It is difficult to predict who will develop nonsegmental vitiligo. Segmental disease limited to the perineal and perianal areas is more common in females. 

The prevalence of vitiligo in childhood and adolescent patients is between 1.52% and 2.16%. Congenital vitiligo is rare but cases have been reported.

Genital vitiligo has been associated with the Koebner phenomenon, with new lesions appearing in previously unaffected areas following traumatization of the skin. The genital area in infants and toddlers is subjected to regular friction and trauma from body fluids, particularly when wearing diapers.

While the precise etiology of vitiligo remains debated, the leading hypothesis implicates both genetic and environmental factors that lead to an innate immune response resulting in CD8+ T-cell activation, release of interferon-γ (IFN-γ), and an associated inflammatory cascade in keratinocytes via the JAK/STAT pathway.

Environmental factors include mechanical trauma and/or exposure to depigmenting agents.

While most vitiligo patients are otherwise healthy, an association with autoimmune thyroid dysfunction (hyperthyroidism or hypothyroidism) has been demonstrated. In new-onset vitiligo patients with systemic symptoms, thyroid screening with antithyroid peroxidase (TPO) antibody and a serum thyrotropin is recommended. Additional associations include endocrinopathies, such as diabetes mellitus and Addison disease, along with other autoimmune processes. Rarely, it may exist as part of polyglandular autoimmune syndrome, particularly a type III syndrome (eg, Hashimoto thyroiditis or alopecia areata and/or another organ-specific autoimmune disease). Vitiligo may accompany halo nevi. New-onset vitiligo may be seen in patients with metastatic melanoma. It can occur spontaneously and may herald metastatic disease, or it can be triggered by immunotherapy such as with BRAF inhibitors or PD-1 inhibitors. In the latter setting, it is considered a good prognostic sign. Rarely, vitiligo may be associated with uveitis. An increased risk of developing sensorineural hearing loss has been identified in both adults and children with vitiligo. Additionally, there is an increased risk of mixed (sensorineural and conductive) hearing loss in children.

Vitiligo carries a psychosocial burden and negatively impacts the quality of life of children affected by the condition. Genital disease can be particularly distressing for young patients, given the sensitive location. Mental health conditions have been associated with vitiligo, including anxiety, depression, panic disorder, and attention deficit hyperactivity disorder (ADHD). In adolescents and adults, this may also impact sexual activity and their relationships with partners.