What precisely causes Lichen planus has not been plainly comprehended till date yet different
speculations have existed in the matter of what can trigger this condition in some individuals and not in
others. A percentage of the regularly refered to reasons include :

• A hypersensitive or resistant response to a pharmaceutical or other substance has been emphatically
  supported as the reason for this condition. It’s thought to be an auto-insusceptible malady in which the
  body’s defensive cells assault the body’s own particular tissues mixing up them to be outside in nature.
• Certain cases have been connected to contaminations, for example, hepatitis C
• Quite a couple of medications, for example, those containing arsenic, bismuth, gold can result in a
  response like the rash of lichen planus
• Chemicals, for example, those utilized within the advancement of color photos can likewise deliver a
  comparable rash
• Long-term utilization of medications like quinacrine or quinidine (against malarial medication) may
  create hypertrophic lichen planus. Some different medications that can trigger these sort of injuries
  incorporate Nsaids (Non-steroidal mitigating medications), certain anti-toxins (Dapsone, Penicillamine,
  Tetracycline, Sulfonamide), pharmaceuticals to treat hypertension (Captopril, Propranolol, Methyldopa,
  Enalapril), Furosemide, Allopurinol, and so on.
• Stress – Intense and delayed passionate push, for example, bitterness, tension, and so on can trigger
  an irregular working of the resistant framework that can prompt Lichen planus.
• Genetic reason
• Amalgam dental fillings may trigger hypersensitive responses offering ascent to oral sores of lichen
  planus