Lichen planus, also known as lichen planus, is a superficial fungal disease caused by infection with Sphaerococcus furfur, so lichen planus is not due to genetics, but is caused by fungal infection. Most patients with pemphigus foliaceus are moist, sweaty, or suffer from anemia, high blood sugar, or obesity. Patients with poor skin barrier function are more susceptible to fungal infections, and fungal reproduction leads to the growth of pemphigus foliaceus. Since lichen planus is caused by fungus, you need to pay attention to bathing and changing clothes regularly to avoid moist and sweaty skin. Topical treatment is mainly with topical antifungal medications, or you can use antifungal lotions, such as ketoconazole lotion, to apply topically while bathing, and oral antifungal medications for those who are stubborn.