The ear has three main parts: external, middle, and inner. These three parts work together so you can hear and process sounds. The outer ear is called the pinna (or auricle) and is made up of ridged cartilage covered by skin. After sound waves enter the outer ear, they travel through the ear canal and make their way to the middle ear, by vibrating the tympanic membrane. The tympanic membrane separates the outer ear from the middle ear and the ossicles. These are the three smallest bones in the human body. These three bones are named the malleus (hammer), the incus (anvil), and the stapes (stirrup). The vibrations are then conducted to the cochlea, which is part of the inner ear. It transforms sound into nerve impulses that then travel to the brain. The fluid-filled semicircular canals (labyrinth) attach to the cochlea and nerves in the inner ear. They send information on balance and head position to the brain. The eustachian tube drains fluid from the middle ear into the pharynx behind the nose.
In ICD-10-CM, the codes for Diseases of the Ear and Mastoid Process are located in Chapter 8. There are currently no guidelines for this chapter. Diseases of the external ear include codes for otitis externa, swimmer’s ear, and hematoma of the pinna. This is where the codes for cerumen impaction will also be found.
The section for the middle ear includes the codes for otitis media, one of the most common diseases in childhood. The two main types of otitis media are acute otitis media (AOM) and otitis media with effusion (OME). AOM is usually caused by bacteria, usually Streptococcus pneumoniae or Haemophilus influenza; but sometimes by a virus, like respiratory syncytial virus. OME occurs when there is thick or sticky fluid behind the eardrum in the middle ear, but there is no ear infection. Swelling of the lining of the Eustachian tube can be caused by many factors, including allergies, irritants (especially cigarette smoke), and respiratory infections. OME is most common in winter or early spring, but it can occur at any time of year. It can affect people of any age, although it occurs most often in children under age 2, according to the Center for Disease Control. There are many more codes in this section compared to ICD-9-CM due to laterality in the code set. Some examples include:
H65.22 Chronic serous otitis media, left ear
H66.001 Acute nonsuppurative otitis media without spontaneous rupture of ear drum, right ear
H66.23 Chronic atticoantral suppurative otitis media, bilateral
The section for the inner ear includes codes for otosclerosis, vestibular function disorders, and labyrinthitis. Documentation for auditory conditions should include the type of disorder and the ear, or ears, affected in order to assign the codes to the highest level of specificity available in ICD-10-CM.