The mastoid is a trabeculated honey-combed air cell system found behind the ear that is connected to the middle ear space. Mastoiditis, or infection of the mastoid bone, may be either acute or chronic. Sudden, rapid infection of the mastoid may be life-threatening and should be treated as a medical emergency usually requiring urgent surgical therapy. Chronic infections often include a perforation of the eardrum and recurrent drainage in a condition called chronic otitis media. Antibiotics in topical form or by mouth may bring about resolution of symptoms. In many cases, however, surgical removal of the infected bone with a mastoidectomy is necessary to alleviate the infection restoring the ear to health.