Lichen planus can occur in anyone at any age, but there are certain factors that make some people more likely to develop the condition. The skin form of lichen planus occurs in men and women equally, but women are twice as likely to get the oral form. It is very rare in young and elderly people, and most common in middle-aged people.
Other risk factors include having other family members with lichen planus, having a viral disease like hepatitis C, or being exposed to certain chemicals that may act as allergens. These could be antibiotics, arsenic, gold, iodide compounds, diuretics, and certain kinds of dyes.