Cause of Lichen Planus is unknown. But certain conditions can trigger Lichen Planus-
- Stress - Stress can trigger Lichen Planus.
- Viral Infections - Sometimes Viral infections especially Hepatitis C can trigger Lichen Planus.
- Genetics - Lichen Planus usually run in families.
- Allergic reaction - Allergic response of body to certain chemicals, dyes, medicinal substances, dental products can cause Lichen planus.