Middle Ear Conditions (Acute Suppurative Otitis Media (ASOM))

What is Acute Suppurative Otitis Media?

ASOM is an infection of the middle ear space. Children are more commonly affected although adults are susceptible. The pathophysiology of ASOM is typically an ascending infections from the nasopharynx up the Eustachian tube to the middle ear. The primary infection can take the form of a viral upper respiratory tract infection (URTI), an acute sinusitis or a lower respiratory tract infection. The purported reasons why children are most susceptible include ineffective Eustachian tube function, chronic adenoidal infection and frequent URTI as a result of schooling. The pathogens include Haemophilus influenzae, Beta-haemolytic Streptococcus and Moxarella catarrhalis.

Symptoms and Signs

In the early stages, there will be some discomfort, sensation of blockage and deafness. As the condition progresses, otalgia becomes the principal complaint, associated with fever and toxicity. There is usually a history of preceding URTI.
On examination, the patient will look ill, with a fever of more than 38 Celsius. The appearance of the eardrum differs during the stages of ASOM. In the first 48 hours, the eardrum is erythematous with some retraction. From two to seven days, there will be accumulation of pus and a bulging tympanic membrane, with pus clearly seen in the middle ear. From then on, as te conditions resolves, the eardrum appears more opaque and less erythematous and bulging.

Investigations

In an acute infection, no investigations are generally warranted. If the infection ruptures the eardrum, a culture and sensitivity of the discharge can be taken.

Management

The management of ASOM is mainly conservative. Pain relief and antipyretics (paracetamol, codeine) are usually required. Antibiotics (Augmentin, Klacid) are generally prescribed although some studies have questioned their efficacy. The symptoms and signs should resolve over three to five days after commencement of treatment. If the symptoms are present after one week, or worsen, a myringotomy should be performed and drainage established.

Complications

Complications from ASOM are uncommon with prompt and effective treatment. The most common complication is perforation of the tympanic membrane resulting in ear discharge and relief of pain. Infection can also spread medially to the inner ear, causing labyrinthitis with deafness and vertigo. It can also spread posteriorly, resulting in an acute mastoiditis with postauricular swelling and pain. Meningitis and facial paralysis are very rare complications.