Lichen planus and chronic hepatitis C: exacerbation of the lichen under interferon-alpha-2a therapy.

A 51-year-old man was treated for histologically proven chronic hepatitis C with 3 MU of recombinant interferon-alpha-2a three times a week. Before interferon therapy, a mild lichen planus (hypertrophic variant) had been diagnosed, which exacerbated within 6 weeks of treatment to a severe erosive oral form. Then interferon therapy was stopped because local measures did not improve oral lesions. However, the patient tolerated interferon therapy well, and the initially four-fold elevated aminotransferase levels returned to normal. Nine weeks after discontinuation of interferon therapy, nearly all the buccal mucous membrane lesions had disappeared. But 8 weeks after withdrawal of interferon, aminotransferase levels rose again to six times the normal range. Treating physicians should know that a pre-existing lichen planus would potentially exacerbate, as a side effect of interferon-alpha-2a therapy of chronic hepatitis. However, further observations are needed to decide its clinical relevance.