Childhood lichen sclerosus (LS) is a rare and often misdiagnosed inflammatory dermatitis with an unpredictable course. The complications of LS are architectural changes of the vulva; malignant transformation is possible. The objective of our study was to define the background and the long-term course of childhood LS. A registery study identified 44 children with LS treated at Tampere University Hospital, Tampere, Finland, from 1982 to 2010. A questionnaire was sent to the identified patients and 15 responded. The clinical depiction of LS varied significantly. LS was diagnosed in only 16% of the patients at the referring unit. Autoimmune disorders were observed in 6 of the 44 patients. High prevalences of Turner's syndrome (2/44) and kidney disease (2/44) were noted. The majority of the patients were treated with topical corticosteroids. Eight developed architectural changes of the vulva. The questionnaire revealed that three of six patients who were asymptomatic at the end of the registery study follow-up experienced a recurrence of symptoms. None of them were undergoing follow-up. Nine of the 15 patients reported reduced quality of life. Childhood LS is a heterogeneous disease with a remarkable effect on quality of life. The misdiagnosis of childhood LS is common. The association between LS and autoimmune diseases should be noted. The high prevalence of Turner's syndrome raises questions regarding the influence of low estrogen levels on the development of LS. The prognosis cannot be predicted, so long-term follow-up is recommended. New tools for diagnosis and surveillance are needed.