Middle ear disorders may be secondary to infection, eustachian tube obstruction, or trauma. Information about objects placed in the ear and symptoms such as rhinorrhea , nasal obstruction , sore throat , upper respiratory infection , allergies , headache , systemic symptoms, and fever aid in making a diagnosis. The appearance of the external auditory canal and tympanic membrane often yields a diagnosis. The nose, nasopharynx, and oropharynx are examined for signs of infection and allergy and for evidence of tumors .