The first reported case of lichen planus following inactivated influenza vaccination.

Lichen planus (LP) is an idiopathic, inflammatory, pruritic dermatosis of unknown origin. An increased prevalence of a wide range of diseases such as viral hepatitis C, hepatitis B, primary sclerosing cholangitis, and primary biliary cirrhosis have been associated with LP. Recently, LP has been reported following administration of different types of hepatis B vaccines but a relationship with an inactivated influenza vaccine (Fluarix, GlaxoSmithKline) has not been reported previously. We present a case of generalized LP manifesting 7 days after the first 0.5-ml dose of influenza vaccine, administered via deltoid injection. LP is possibly a viral antigen-triggered inflammatory skin condition, the pathogenesis of which needs to be further explored.