Background: Annular lichen planus is a clinical variant of lichen planus, and its characteristic lesions are annular plaques consisting of a narrow rim of activity and a depressed center.
Objective: This article presents two cases of annular lichen planus, a 39-year-old woman and a 45-year-old woman.
Methods and results: In both cases, lesions developed mainly on the femoral regions. Histopathological specimens from the margin of the lesion demonstrated liquefaction degeneration of the epidermis and band-like infiltrate of lymphocytes in the upper dermis, whereas there was very mild infiltrate in the upper dermis from the center. In the center, elastic fibers were more fragmented and less numerous than in the margin. Although topical corticosteroid tape was effective for one case, new lesions developed several times over two years in the other.
Conclusion: Our findings suggest that this clinical behavior is from elastolysis as a result of inflammation.