You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is All of the following regarding Lichen planus are true except - and explain in detail?
Mucous membranes are commonly involved especially of oral mucosa, and less commonly of genital tract.
Hepatitis 'C' and chronic active hepatitis have been implicated for the causation of Lichen planus.
Topical steroids are the first line of treatment.
Lesions of Lichen planus heal spontaneously in 6 months to 2 years, leaving behind hyperpigmentation.