Immunoperoxidase evaluation of lichen planus biopsies for hepatitis C virus

Background Lichen planus is a papulosquamous dermatosis which has recently been linked to infection with hepatitis C virus. It is unclear whether or not viral antigens may be present in the cutaneous lesions of lichen planus. Materials and methods Twenty-five paraffin-embedded samples of glabrous lichen planus were evaluated using immunoperoxidase staining for the presence of hepatitis C virions. Control tissues consisted of hepatitis C-infected hepatic tissue (n = 2), normal hepatic tissue (n = 2), normal human skin (n = 1), and two cutaneous biopsies of lichen planus from persons known to be infected with hepatitis C. Results The sections of hepatitis C-infected liver tissue stained positive for hepatitis C virions. The 25 biopsies of glabrous lichen planus, the two biopsies of lichen planus from hepatitis C patients, the two sections of normal liver, and the one normal skin sample all failed to take up the stain. Conclusions Cutaneous lesions of lichen planus are more probably reactive to the underlying infection than a manifestation of skin involvement by this disease. This theory is supported by the histologic findings in a lichenoid drug eruption, which are virtually identical to those of idiopathic lichen planus. Insufficient sensitivity by the immunoperoxidase procedure used is a possible explanation for our results; however, it appears more probable that no virus exists at the sites of cutaneous involvement.