Lichen planus has a chronic course and most patients disappear on their own within about 2 years of onset, but some patients may persist for several years. The most common cause of warts is human papillomavirus infection, which is a viral skin disease that occurs in adolescents and young adults. It is often sudden in onset and can disappear on its own after 1-2 years. The main manifestation is a flat, elevated papule, round or rounded in shape, which is usually found on the face and upper extremities. There are usually no obvious conscious symptoms, and occasionally there is mild pruritus. When the rash suddenly increases or the itching intensifies, it often indicates that the disease is about to heal and is a sign that the lesions are fading. If the patient does not heal for several years, the patient needs antiviral treatment and, if necessary, photodynamic therapy. In addition, patients with flat warts need to be careful to avoid scratching to avoid self-infection, which can lead to the spread of the rash.