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Overview and Clinical Classification of Vitiligo — Diagnostic Context of Non-segmental and Segmental Vitiligo

Vitiligo is a common acquired depigmenting skin disorder with a global prevalence of approximately 0.5% to 2%. The core pathological change involves the destruction or loss of function of melanocytes in the basal layer of the epidermis, rendering the skin unable to synthesize melanin normally, which in turn leads to the formation of well-demarcated white patches. Although vitiligo usually causes no severe physical pain or itching, its lesions frequently appear on visible areas such as the face, neck, and hands, often exerting a profound impact on patients' mental health and social life1.

 

In clinical diagnosis, vitiligo is primarily categorized into two main types: Non-segmental Vitiligo and Segmental Vitiligo. These two types differ significantly in their pathological mechanisms, clinical manifestations, and treatment prognoses4.

Clinical Dimension Nonsegmental Vitiligo Segmental Vitiligo
Proportion of Total Cases Accounts for approximately 85% of total cases4 Accounts for approximately 10%–15% of total cases
Lesion Distribution Typically bilateral and symmetrical; common on extremities, face, and joints Distributed along a unilateral dermatome with clear boundaries
Age of Onset & Progression Can occur at any age; progression is usually chronic and gradual More common in children and adolescents; onset is rapid but tends to be self-limiting
Hair Involvement (Poliosis) Hair mostly remains normal in early stages; may turn white in advanced stages Can involve deep follicular melanocytes at an early stage
Autoimmune Association Highly associated with autoimmune thyroiditis, alopecia areata, etc.2 Low association with systemic autoimmune diseases
Treatment Response & Prognosis Responds well to phototherapy and topical immunosuppressants, but prone to relapse5 Poor response to traditional medications and phototherapy; suitable for surgery once stable7

Accurate clinical diagnosis relies on visual examination and auxiliary investigations by a dermatologist. Among these, the Wood's lamp examination is a standard tool for assessing early or subtle skin lesions. Under the long-wave ultraviolet light of a Wood's lamp, depigmented areas emit a distinct bright blue-white fluorescence, rendering hidden micro-lesions and margins visible. This assists doctors in accurately evaluating the extent of the lesions and the activity level of the disease.8。

Reference

  1. British Association of Dermatologists guidelines for the management of people with vitiligo 2021 | Request PDF - ResearchGate, https://www.researchgate.net/publication/352686774_British_Association_of_Dermatologists_guidelines_for_the_management_of_people_with_vitiligo_2021

  2. Vitiligo - Primary Care Dermatology Society, https://www.pcds.org.uk/clinical-guidance/vitiligo

  3. British Association of Dermatologists guidelines for the management of people with vitiligo 2021*, https://bpg.org.uk/wp-content/uploads/2024/01/Br-J-Dermatol-2021-Eleftheriadou-British-Association-of-Dermatologists-guidelines-for-the-management-of-people-with-vitiligo.pdf

  4. China Medical System: New Drug Application of Ruxolitinib Phosphate Cream for Vitiligo Approved in Hong Kong – CMS, https://web.cms.net.cn/en/2024/11/china-medical-system-new-drug-application-of-ruxolitinib-phosphate-cream-for-vitiligo-approved-in-hong-kong/

  5. Vitiligo: Unmet Need, Management and Treatment Guidelines - PMC, https://pmc.ncbi.nlm.nih.gov/articles/PMC10824320/

  6. Treatment for Nonsegmental Vitiligo | OPZELURA® (ruxolitinib), https://www.opzelura.com/vitiligo/

  7. Vitiligo: Diagnosis and treatment - American Academy of Dermatology, https://www.aad.org/public/diseases/a-z/vitiligo-treatment

  8. Professional Vitiligo Treatment in London | The Thomas Clinic, https://thomasclinic.com/conditions-treatments/vitiligo-treatment/