Suppurative otitis media (SOM) is inflammation of the middle ear space defined by the presence of purulent fluid. The middle ear is the air-filled pocket behind the eardrum containing the tiny bones responsible for hearing. When infected, the body’s immune response generates pus that collects and causes pressure. SOM manifests in two primary forms: acute, marked by rapid onset, or chronic, characterized by long-term inflammation and drainage through a persistent eardrum perforation. The term “suppurative” highlights the active bacterial or viral infection causing the pus.
Understanding the Infection Mechanism
The process leading to suppurative otitis media typically begins with dysfunction of the Eustachian tube, the small canal connecting the middle ear to the back of the throat. This tube ventilates the middle ear and equalizes pressure. When the Eustachian tube becomes obstructed or swollen, often due to an upper respiratory infection or allergies, it prevents proper drainage and ventilation. This obstruction creates negative pressure, allowing fluid to build up.
The trapped fluid then becomes a medium for bacterial or viral growth, leading to an active infection. For acute SOM, the most common bacterial culprits are Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis. These pathogens often migrate from the nasopharynx into the middle ear via the dysfunctional Eustachian tube. Chronic SOM is frequently associated with organisms like Pseudomonas aeruginosa and Staphylococcus aureus, which may enter the middle ear through a pre-existing eardrum perforation.
Several factors increase susceptibility to this infection:
- Children under the age of two, whose Eustachian tubes are shorter, narrower, and more horizontally aligned.
- Attending daycare, which increases exposure to respiratory viruses.
- Exposure to cigarette smoke, which irritates the Eustachian tube lining and impairs its function.
- Seasonal allergies, which cause inflammation that further obstructs the tube, setting the stage for microbial invasion.
Recognizing the Clinical Signs
The clinical signs of suppurative otitis media vary depending on whether the condition is acute or chronic. Acute SOM is marked by the rapid onset of intense pain resulting from the pressure of pus against the eardrum. Children often show irritability, difficulty sleeping, or constant ear pulling. A fever, often greater than 102.2°F (39°C), frequently accompanies the active infection.
Hearing reduction is a common complaint, caused by fluid accumulation hindering the movement of the middle ear bones. If pressure becomes too great, the eardrum may rupture, leading to a sudden discharge of pus, called otorrhea, into the ear canal. This rupture often provides immediate pain relief due to the release of pressure.
In contrast, chronic SOM is characterized by persistent otorrhea lasting for six weeks or more through a perforation. Pain and fever are often absent in chronic cases unless a complication, such as the spread of infection, has occurred. The primary symptom is continuous or recurrent discharge, which can be foul-smelling, and a varying degree of hearing loss.
Confirming the Diagnosis
Diagnosis of suppurative otitis media is confirmed primarily through visual examination of the eardrum using an otoscope. During an acute episode, the provider looks for signs indicating pus and inflammation. These signs include a bulging eardrum that appears red or opaque, sometimes with visible fluid levels or air bubbles behind it.
The lack of normal eardrum mobility when air pressure is applied with a pneumatic otoscope further supports the diagnosis of fluid presence. If the eardrum has ruptured, the otoscopic examination will reveal a perforation with visible pus draining. In chronic SOM cases, the examination shows a persistent perforation with active discharge or signs of granulation tissue growth.
Tympanometry, a secondary diagnostic tool, may be used to provide an objective measurement of middle ear pressure and eardrum compliance. This test helps confirm fluid presence by showing an abnormal tracing, indicating a lack of vibration. If a chronic infection is suspected, a sample of the ear discharge is typically sent for a culture to identify the specific bacterial organisms and determine effective antibiotics.
Managing the Infection
For acute SOM, the initial focus is on managing pain and reducing inflammation, typically using analgesics like acetaminophen or ibuprofen. Antibiotic therapy is often initiated immediately for children under six months of age, those with severe symptoms, or those with bilateral infection. High-dose amoxicillin is the preferred first-line antibiotic, though alternatives are used for those with a penicillin allergy.
In mild, non-severe acute SOM cases, a period of “watchful waiting” for 48 to 72 hours may be recommended to see if the infection resolves spontaneously. If symptoms do not improve or worsen, antibiotic treatment is then started.
Treatment for chronic SOM shifts to local management. This often involves rigorous “aural toilet,” the cleaning of the ear canal to remove debris, followed by topical antibiotic drops, such as fluoroquinolones. Oral antibiotics are generally reserved for infections resistant to topical treatment or when signs of spreading infection are present.
Surgical intervention becomes necessary for recurrent or non-resolving cases. A myringotomy, a small incision in the eardrum, may be performed to drain pus and relieve pressure, often combined with the insertion of a tympanostomy (ear tube). These tubes ventilate the middle ear and prevent fluid re-accumulation. For chronic cases, a tympanoplasty to repair the perforated eardrum is often necessary once the active infection is cleared.
Addressing Severe Outcomes
While most cases of suppurative otitis media resolve without lasting problems, a severe or long-standing infection can lead to complications. The most common adverse outcome is temporary or permanent hearing loss. Chronic inflammation can also cause a permanent perforation of the eardrum.
Mastoiditis occurs when the infection spreads to the mastoid bone. This requires immediate medical attention and often involves intravenous antibiotics. In rare instances, the infection can erode the bone and spread beyond the middle ear space.
Spread beyond the middle ear can result in life-threatening conditions, including meningitis or a brain abscess. Other potential severe outcomes include labyrinthitis, an inflammation of the inner ear causing vertigo and profound hearing loss, and facial nerve paralysis.