Which is the underlying mechanism of vitiligo?

Which is the underlying mechanism of vitiligo?

• A. Increased melanin production
• B. Autoimmune destruction of melanocytes
• C. Excess sun exposure causing photodamage
• D. Bacterial infection of melanocytes

Answer: (B)

Vitiligo stems from autoimmune destruction of the pigment-producing cells in the skin, melanocytes. When the immune system targets these cells, they diminish or disappear from affected areas, leading to well‑defined, depigmented patches because there’s little to no melanin produced in those spots. This autoimmune loss of melanocytes, rather than changes in melanin production or external damage, explains the characteristic pale patches. Increasing melanin production would darken skin rather than create white patches, so that option doesn’t fit. Excess sun exposure causes damage but doesn’t specifically erase melanocytes to produce the stable depigmented areas seen in vitiligo. A bacterial infection of melanocytes isn’t the usual mechanism for vitiligo and doesn’t explain the pattern of depigmentation.

Vitiligo stems from autoimmune destruction of the pigment-producing cells in the skin, melanocytes. When the immune system targets these cells, they diminish or disappear from affected areas, leading to well‑defined, depigmented patches because there’s little to no melanin produced in those spots. This autoimmune loss of melanocytes, rather than changes in melanin production or external damage, explains the characteristic pale patches.

Increasing melanin production would darken skin rather than create white patches, so that option doesn’t fit. Excess sun exposure causes damage but doesn’t specifically erase melanocytes to produce the stable depigmented areas seen in vitiligo. A bacterial infection of melanocytes isn’t the usual mechanism for vitiligo and doesn’t explain the pattern of depigmentation.