Hello, If you are talking about lichen planus skin allergy, then it is an autoimmune disease and contributing factors are vitamin D deficiency, genetic predisposition, stress, etc. Get connected to a dermatologist. Get done biopsy and culture tests to confirm bacterium. LP is a lifelong condition that will have to be treated and monitored. Immunosuppressants and corticosteroid creams are helpful. You need specialized care. Avoid oily, spicy, hot food. Avoid sharp food, alcohol and alcohol-based mouth washes. Instead take bland food, boiled food and food cooked in olive oil. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Nupur K, General & Family Physician