my sister is suffering from unknown mouth infection for over a month, almost 2 month. she has many ulcers on her gum, tongue, room, cheek of mouth. Tested for herpes, ( don t know the result yet) however prescribed medicine for herpes is not working yet. there are no improvement moreever it now spread to her thought. She has been to many doctors and dentists but we don t know what is the cause of this.