A lot of medical conditions can affect the ear. The Physician Assistant Exam will expect you to know that otitis (inflammation of the ear) comes in two kinds: otitis externa and otitis media. Although the two conditions share the word otitis, they’re quite different.
Otitis externa (external otitis)
Otitis externa (also called external otitis), as the name suggests, affects the outer ear. You see it in two common scenarios. The first is swimmer’s ear, which you see in someone who does a lot of swimming. Kids are infected more than adults. The other clinical scenario is in someone who’s relatively immunocompromised, such as a person with uncontrolled diabetes.
Otitis externa is very painful. The outer ear is red and inflamed and looks nasty. You may see skin irritation that mimics dermatitis on the ear.
The most common bacterial organism causing otitis externa is Pseudomonas aeruginosa, especially in someone with uncontrolled diabetes. Note that Staphylococcus aureus is also a common cause of otitis externa. Fungal organisms can also be responsible.
If you see a test question concerning either otitis externa or osteomyelitis in someone with diabetes, Pseudomonas is going to be a high-yield answer.
Treatment for otitis externa is antibiotics to relieve the infection and steroids to relieve the inflammation. These are topical solutions.
Otitis media
Otitis media is an inflammation of the middle part of the ear, usually seen in children, although it can also occur in adults. Otitis media has both acute and chronic forms.
This condition is caused by a bacterial infection, the three most common being Streptococcus pneumoniae, Moraxella catarrhalis, and Haemophilus influenzae. Concerning clinical presentation, the person feels significant pain in the ear, especially if you gently pull on the tragus of the ear. Fever can be present, and the child usually looks toxic. The child may be in tears because the ear pain is so bad.
On physical examination, you often notice a lack of the “cone of light” reflex when you look at the tympanic membrane with an otoscope. If you were to do air insufflation of the tympanic membrane in someone with otitis media, that would elicit some pain as well. A lot of pressure is behind the eardrum, which can be painful. In addition, the tympanic membrane can be angry and erythematous.
The treatment of otitis media is antibiotics; the first choice is usually amoxicillin (Amoxil).
Repeated ear infections may mean that myringotomy tubes are needed. These tubes should help over the long haul. Complications of otitis media, if untreated, include mastoiditis, abscess, or meningitis. Over time, repeated infections can affect a kid’s hearing.
The chronic form of otitis media actually involves a rupture of the tympanic membrane. This is a result of an infection that has persisted for several weeks.
Another complication of chronic otitis media is a cholesteatoma, a cyst-like structure filled with squamous epithelium that can destroy surrounding structures. It can occur in the middle ear or in the mastoid bone.
Common initial symptoms can include pain, ear drainage, and hearing loss. On otoscopic examination, you can see a lot of scar material that doesn’t get better with antibiotics. The best imaging study is a CT scan of the head to look further at the bone. The treatment is primarily to remove the cholesteatoma surgically.