Vitiligo is a common, often heritable disorder that is progressive in nature. It is characterized by cutaneous macules and patches devoid of pigmentation. The lesions are not readily apparent in lightly pigmented individuals; however, they are easily distinguishable with a Wood lamp examination.
Vitiligo lesions may be localized or generalized, with the latter being more common than the former. Localized vitiligo is restricted to one general area with a segmental or quasidermatomal distribution. Generalized vitiligo implies more than one general area of involvement. In this situation, the macules are usually found on both sides of the trunk, either symmetrically or asymmetrically arrayed.
Sites of involvement
The most common sites of vitiligo involvement are the face, neck, and scalp. In generalized vitiligo, mucous membranes are also frequently involved. Most of the time vitilogo occurs around body orifices such as the lips, genitals, gingiva, areolas, and nipples.
Body hair (leukotrichia) in vitiliginous macules may be depigmented. Vitiligo of the scalp usually appears as a localized patch of white or gray hair, but total depigmentation of all scalp hair may occur. Scalp involvement is the most frequent, followed by involvement of the eyebrows, pubic hair, and axillary hair, respectively. Leukotrichia may indicate a poor prognosis in regard to repigmentation. Spontaneous repigmentation of depigmented hair in vitiligo does not occur.
Clinical Variants of VITILIGO
Trichrome vitiligo refers to the presence of an intermediate zone of hypochromia located between the achromic center and the peripheral unaffected skin. The natural evolution of the hypopigmented areas is progression to full depigmentation. This results in 3 shades of color—brown, tan, and white.
Quadrichrome vitiligo is another variant of vitiligo, which reflects the presence of a fourth color (ie, dark brown) at sites of perifollicular repigmentation.
Marginal inflammatory vitiligo
Marginal inflammatory vitiligo results in a red, raised border, which is present from the onset of vitiligo (in rare cases) or which may appear several months or years after the initial onset. A mild pruritus may be present.
Blue vitiligo results in blue coloration of vitiligo macules. This type has been observed in a patient with postinflammatory hyperpigmentation who then developed vitiligo.
Koebner phenomenon is defined as the development of vitiligo in sites of specific trauma, such as a cut, burn, or abrasion. Minimum injury is required for Koebner phenomenon to occur.