[Study of lichen planus conducted by the IGESD: results, implications for clinical practice, prospects. Italian Group of Epidemiological Studies in Dermatology (IGESD)].

Between September 1986 and February 1988 the Italian Group for Epidemiological Research in Dermatology (GISED) conducted a multicentre case-control study concerning etiological factors for lichen planus. 711 cases of lichen planus and 1395 dermatological controls were selected. Various indicators of liver disorders, including history of liver diseases requiring hospital admission/specialist consultation, high transaminase levels, positive tests for hepatitis B virus surface antigen, and history of liver biopsies were risk factors for lichen planus. In addition, ulcerative colitis and alopecia areata were found to be significantly associated with lichen planus. Giving these results, several considerations were done for the clinical practice, including the suggestion that a screening for liver diseases is advisable in lichen planus patients. A cohort study is now underway to trace the natural history of lichen planus and to better define the liver disorder in lichen planus patients.