Nothing can be said unambiguously about the exact causes of lichen planus. It is also considered as an autoimmune disorder, which can also affect the immune system. It can also happen in different parts of the skin. It can also affect your skin, oral health and internal organs. However it is not a contagious condition. You can get some relief from it by reducing its symptoms but for its treatment know about the causes and symptoms of lichen planus in detail.