Lichen sclerosus is the thinning of the vulvar skin. While the cause is unknown, theories range from autoimmune disorders, to genetic and hormonal causes. Patients are most frequently postmenopausal females who may either be pruritic or asymptomatic. The thinning starts as symmetrical white thin skin (vulva, perianal) that progresses to loss of the labia minora, though the condition spares the vagina.
Grossly, there are white flat plaques (leukoplakia), which mimics other lesions. The appearance is that of thin parchment paper, and there may be superficial ulceration. The microscopic appearance varies according to the age of the lesion, excoriation, and treatment status.