Labial adhesion consists of fusion of the labia. It is most common in prepubertal girls, ages 3 months to 6 years, with a peak in incidence between 1–2 years. It is thought to be due to irritation and resulting inflammation that heals inappropriately in conjunction with decreased estrogen. After puberty, it is usually the result of vulval trauma, surgical procedure, hypoestrogenism, or chronic infection causing inflammation. After menarche, labial adhesions from sexual abuse are rare.