Vitiligo

Vitiligo affects the skin and, in some cases, the hair. The immune system is thought to attack and destroy melanocytes, the cells that produce the pigment melanin, and as those cells are lost the skin develops smooth patches without color. The autoimmune theory is the most widely accepted explanation, and researchers describe a process in which melanocyte stress and dysfunction help trigger the immune response that ultimately destroys them, with newer research pointing to type I interferon and JAK/STAT signaling as part of that pathway.

Vitiligo is estimated to affect roughly 0.5 to 2 percent of people worldwide, with most reviews citing a figure near 1 percent, and it can begin at any age. People with vitiligo are also more likely to have other immune-mediated conditions, thyroid disease among the most common, so clinicians often screen for related conditions once vitiligo is diagnosed.

Common signs

Smooth white or lighter patches of skin that often begin on the hands, forearms, feet, and face and may slowly spread. The patches are usually not itchy or painful, and hair growing in affected areas can also turn white. The condition is most visible on darker skin tones.

This is a plain-language summary for orientation, not a diagnosis. Mechanisms are described as current understanding, not settled fact. Work with your own clinician for your care.