Lichen sclerosus

Lichen sclerosus is a chronic inflammatory condition that most often affects the genital and anal skin. Current research points to an immune-driven Th1 response, in which environmental factors acting on a genetically susceptible person set off a chronic inflammatory state that damages tissue and activates pathways involved in collagen buildup, ultimately leading to the thinned, fragile, whitened skin that characterizes the condition. Older hypotheses also considered infectious triggers and a reaction to prior skin trauma, and it is likely that more than one mechanism contributes across different people.

Lichen sclerosus most often develops in postmenopausal women, though it can affect men and children too, with children accounting for an estimated 7 to 15 percent of cases. Estimates of how common it is range from roughly 1 in 300 to 1 in 1,000 people, and because it is under-recognized, the true prevalence may be higher.

Common signs

Smooth white, often crinkly or shiny patches, most often around the vulva, penis, or anus, with itching, soreness, and sometimes pain. The thinned skin can crack, bruise, or tear easily, and discomfort with urination, bowel movements, or intimacy is common. Untreated disease can lead to scarring, narrowing of the affected opening, and a small increased skin cancer risk over time.

This is a plain-language summary for orientation, not a diagnosis. Mechanisms are described as current understanding, not settled fact. Work with your own clinician for your care.