Lichen sclerosus et atrophicus affecting the wrists and left ankle and clinically simulating lichen planus.

Lichen sclerosus et atrophicus (LSA) is a disease of unknown etiology, although hereditary, endocrine, and autoimmune factors are known to be involved. Although the anal and genital regions are predominantly affected, 2.5% of patients only present with extragenital lesions--particularly of the trunk, neck, and upper limbs. The wrists, palmoplantar regions, nipples, and face are less commonly involved. The possible relationship between LSA and both lichen planus and localized scleroderma (morphea) has not been clearly established, although in a number of cases, several of these conditions have been found simultaneously. We report the case of a 61-year-old woman with LSA lesions affecting only the wrists and left ankle. The unusual character of this presentation is pointed out, along with its clinical similarity to lichen planus.