The high rate of familial lichen sclerosus suggests a genetic contribution: an observational cohort study.

Background: Familial lichen sclerosus (LS) has been described in only 37 families. We feel that the association is under-reported.

Objectives: To determine the percentage of patients with LS who have a positive family history.

Method: A large observational-cohort study of a total of 1052 females at vulval clinics within a University Hospital with a diagnosis of LS of the vulva (clinical diagnosis was confirmed in 80% of cases by histology). Patients were questioned as to family history of LS or balanitis xerotica obliterans; male circumcision for medical reasons; vulval cancer; and routine medical and family history. The outcome was the presence or absence of personal or family history of LS, autoimmune disorder or vulval cancer.

Results: In total 1052 patients were investigated. Of these, 126 (12%) had a positive family history of LS. These patients belonged to 95 families. Vulval cancer was significantly increased in those with a family history of LS compared with those without (4.1% vs. 1.2%, P < 0.05). There was more associated autoimmune disease in familial LS than in sporadic LS, although this was not statistically significant. (7% vs. 5%, P > 0.2).

Conclusion: Our data from a large cohort of patients with LS provide evidence of an increased risk for family members to develop LS. This indicates a likely genetic component in the aetiology of LS.