Lichen planus might be associated with

Lichen planus may be associated with hepatitis C infection The presence of hepatitis is often completely unknown to the patient, being discovered by chance during diagnostic protocol for lichen planus. Prevalence of chronic hepatitis C in patients with oral lichen planus varies between 0.5-35% as repoed by different authors for different geographical areas. The other associations may be vaccinations, dental amalgum, autoimmune diseases. Ref Harrison 20th edition pg 1211 .Harrison 19e pg: 349