Lichen planus pigmentosus

The disease usually appears in the third and fourth decade of life. The lesions are asymptomatic or mildly pruritic. Skin changes are dark brown or slate grey macules or papules with, in most cases, a diffuse pigmentation pattern. They most commonly affect the face, neck and upper limbs. Predominantly a intertriginous disease, usually in the axillae and groin (described mostly in Caucasians), it has also been termed as lichen planus pigmentosus inversus. The scalp, nails or mucosa are not affected. LP pigmentosus can exist in association with typical LP lesions.