Etiology
The tympanic membrane is in the deep external auditory canal and plays an important role in the process of sound transmission. Tympanic membrane trauma is mostly caused by indirect or direct external forces, and can be divided into instrument injury, such as tympanic membrane perforation caused by sharp earpicks; iatrogenic injury, caused by extraction of cerumen or foreign bodies in the external auditory canal; burns, caused by slag and sparks; pressure injury, caused by slapping, exposures to blasting, artillery shock, and firecrackers, high diving, and diving. Tympanic membrane trauma can also be caused by longitudinal fracture of the temporal bone.
Clinical manifestations
After the tympanic membrane ruptures, there is sudden ear pain, immediate hearing loss accompanied by tinnitus, little hemorrhage in the external auditory canal, and sudden aural fullness. Simple tympanic membrane rupture causes mild hearing loss. In addition to causing tympanic membrane rupture, pressure injury can also cause damage to the inner ear due to violent movement of the stapes, resulting in dizziness, nausea, and mixed hearing loss.
Figure 1 Traumatic perforation of the tympanic membrane
Examination
The tympanic membrane presents mostly irregular perforation or slit. There may be bloodstains or blood crust in the external auditory canal, and small amounts of bloodstains can be seen at the edges of the perforation. Large amounts of hemorrhage or fluid suggest that there may be cerebrospinal fluid otorrhea caused by temporal bone fracture or skull base fracture. The hearing test shows conductive hearing loss or mixed hearing loss.
Treatment
Foreign bodies, blood clots, and pus in the external auditory canal should be removed.
Infection from the nasopharynx should be prevented. If there are no signs of infection, antibiotics are not necessary.
If there is no secondary infection, external auditory canal irrigation or drops are contraindicated. Before the perforation heals, swimming or any fluid entering the ear is prohibited. Traumatic perforation can mostly heal spontaneously within 3 - 4 weeks. For large perforation, the residual edges of the tympanic membrane flipped into the tympanic cavity can be restored in microscopy under sterile conditions, and sterile paper on the surface can promote the healing of the tympanic membrane. In patients with unhealed perforation, tympanoplasty can be performed.
Prevention
Sharp earpicks are prohibited, Extraction of foreign bodies or earwax from the external auditory canal should be careful and gentle. In case of exposure to blasting, ears can be plugged with cotton or fingers, and protective earplugs have better effect.