<prompt> Answer this question truthfullyWhat is Mastoiditis and where can I obtain further information about it?  <response>: <reason> Posterior ear inflammation and redness in physical examinationThe simplest way to detect an active infection in the middle ear is to look in the childs ear with an otoscope, a light instrument that allows the physician to examine the outer ear and the eardrum.There are several ways that a physician checks for middle ear fluid:The use of a special type of otoscope called a pneumatic otoscope allows the physician to blow a puff of air onto the eardrum to test eardrum movement. An eardrum with fluid behind it does not move as well as an eardrum with air behind it.Tympanometry is a test requiring insertion of a small soft plug into the opening of the childs ear canal, providing information indicative of hearing loss from middle ear congestion.Physician may use CT scan in order to detect complications. 