Lichen sclerosus et atrophicus (LSA) is a chronic skin disease characterized by white, flat papules with an erythematous halo and black, hard follicular plugs. In advanced cases, the papules tend to coalesce (blend) into large, white patches of thin, itchy skin.

Lesions often occur on the torso and, almost invariably, in the anogenital (relating to both the anal and the genital) regions. In the latter case, the disease is called kraurosis vulvae.

LSA has the appearance in the skin of pale patches...