๐ ็ธฝ็ฎ้ ๏ฝ ๐ ่ฑๆๅๆ๏ผๆฌ็ฏ๏ผ ๏ฝ ๐ ๅฎๆด็ฟป่ญฏ ๏ฝ โญ ็ฒพ่ฏ็ญ่จ
EPIDEMIOLOGY
Lichen sclerosus is relatively uncommon, although the exact prevalence is unknown. It occurs at all ages with a similar incidence in all races; the reported female-to-male ratio varies widely, depending upon the study, from 10โ:โ1 to 1โ:โ1. In both sexes, the anogenital area is affected in ~85% of patients, but the best epidemiologic studies concentrate on vulvar disease.
Studies in adult patients suggest that LS is one of the most common causes of symptomatic vulvar disease. In two large series, LS was diagnosed in 13% to 19% of patients presenting with symptomatic vulvar disease. In women, the peak incidence is during the fifth and sixth decades, and a second peak occurs in girls between 8 and 13 years of age. Among prepubertal girls with vulvar disease, the relative frequency of LS is similar to that in adults. Extragenital LS is rare in children. In boys and men, LS frequently leads to phimosis (seen in 14 of 100 prepubertal boys undergoing circumcision for phimosis). Of 357 male patients attending a dermatology clinic because of genital skin disease, 14% had LS.
A recent retrospective analysis demonstrated a high prevalence of LS in patients with plaque-type morphea and generalized morphea. This coexistence suggests either a common trigger or a common susceptibility factor for both diseases.