Acute Mastoiditis, How can it happens?

 

Acute mastoiditis was a relatively common condition in children before the introduction of antibiotics. Because the mastoid air cells connect with the middle ear, the process of fluid collection and infection in the mastoid is usually the same as in the middle ear. Early and frequent treatment of acute otitis media is most likely the reason that the incidence of acute mastoiditis has declined to only 1.2 to 2.0 cases per 100,000 person-years in countries with high prescribing rates for acute otitis media. In countries like the Netherlands, where antibiotics are used sparingly for acute otitis media, the incidence rate of acute mastoiditis is roughly twice that seen in countries like the United States. However, neighboring Denmark has a rate of acute mastoiditis similar to that in the Netherlands but an antibiotic-prescribing rate for acute otitis media more similar to that in the United States. In typical acute mastoiditis, purulent exudate collects in the mastoid air cells, producing pressure that may result in erosion of the surrounding bone and the formation of abscess-like cavities that are usually evident on CT. Patients typically present with pain, erythema, and swelling of the mastoid process along with displacement of the pinna, usually in conjunction with the typical signs and symptoms of acute middle-ear infection. Rarely, patients can develop severe complications if the infection tracks under the periosteum of the temporal bone to cause a subperiosteal abscess, erodes through the mastoid tip to cause a deep neck abscess, or extends posteriorly to cause septic thrombosis of the lateral sinus. Cultures of purulent fluid should be performed whenever possible to help guide antimicrobial therapy. Initial empirical therapy is usually directed against the typical organisms associated with acute otitis media, such as S. pneumoniae, H. influenzae, and M. catarrhalis. Some patients with more severe or prolonged courses of illness should be treated for infection with S. aureus and gram-negative bacilli (including Pseudomonas). Broad empirical therapy is usually narrowed once culture results become available. Most patients can be treated conservatively with intravenous antibiotics; surgery (cortical mastoidectomy) can be reserved for complicated cases and those in which conservative treatment has failed.

Source: Harrison_s_Principles_of_Internal_Medicine_16th_Edition