Lesions consist of flat, sharply circumscribed, depigmented macules or zones, which are often noticed before the age of 20 years.
- macules may vary in size from a few millimeters to much larger patches and often consist of scalloped, convex margins (1)
- patches may merge to form extensive geographical patterns (1)
- usually redness of the skin cannot be seen
- can have a "trichrome" appearance (white centre with an intermediate, pale area around it) (4)
- occasionally erythema and heprpigmentation can be seen at the edges of the advancing lesions (1)
- melanocytes in the hair roots may be affected causing white eyelashes and white hair within the depigmented patches (3).
- increased susceptibility to sunburn and itch may be associated with developing lesions (1).
In caucasians, lesions may only become apparent when the surrounding normal skin is tanned, though if required they may be seen under Wood's UV long wave light, which exposes covert variations in pigmentation.
Apart from these possibly cosmetic effects however, the lesions are asymptomatic.
In non-segmental vitiligo
- macules have a clear border with homogenous depigmentation (5)
- the lesions tend to occur symmetrically, and they are often annular, though other patterns do occur
- once formed, the areas of pigment loss tend to enlarge peripherally producing areas which may vary considerably in size. Rarely, the entire body is involved.
- areas involved, often include the fingers, hands, face, mouth, eyes and genitalia (4). Extensor surfaces may also sometimes be involved preferentially
- loss of hair pigment seen in later stages of the disease (5)
In segmental vitiligo
- The borders are more irregular and there is less homogenous pigment loss (5)
- in most of the patients one unilateral segment is involved but there can be involvement of two or more segments on the same or opposite sides
- depigmentation may be seen along the distribution of a dermatome (4)
- hair involvement seen soon after onset (5)
It is thought that vitiligo shows the koebner phenomenon where lesions may be induced in areas of repeated trauma (5).
Reference:
- (1) The Vitiligo Society. What’s new in vitiligo?
- (2) Murphy GF & Mihm MC, in Robbins Pathologic Basis of disease, ed. Cotran, Kumar & Robbins, 1989, 4th edition, Pub. WB Saunders, pg 1278-1279.
- (3) Kirby JTD, in Clinical Medicine, Ed. Kumar & Clark, 1990, 2nd edition, Pub. Balliere Tindall, pg 1045-1046.
- (4) Taïeb A, Picardo M. Vitiligo. NEJM 2009;360:160-169
- (5) Gawkrodger D.J. et al. Guideline for the diagnosis and management of vitiligo. BJD 2008;159:1051-1076