Lichen planus pigmentosus on a man's torso and arms. This is a rare variant of lichen planus characterised by dark brown or grey macules (discoloured areas) on the skin. Areas that are exposed to the sun such as the face, neck and upper limbs are most commonly affected. There is no treatment but lichen planus can be managed by reducing sun exposure and with vitamin A, topical corticosteroids and laser therapy.