Contact precaution if drainage not contained by dressing
Acute mastoiditis is a complication of acute otitis media.
This remains a clinical diagnosis, as imaging of many uncomplicated AOM will reveal fluid in the mastoid air cells.
Minimum diagnostic criteria must include signs of a bulging or recently perforated tympanic membrane (consistent with AOM) and history of short symptom duration (usually less than 2 weeks) with fever, otalgia, and pinna position pointing outward, often with swelling/redness and tenderness over the mastoid area. The pathogens are the same as those that cause AOM (S. pneumoniae, Group A streptococcus, H. influenzae, and rarely S. aureus). The management principles include relieving obstruction (if not perforated) with middle ear drainage (myringotomy with or without myringotomy tube) and antimicrobials.
If bone destruction or abscess in mastoid, mastoid irrigation and drainage +/- mastoidectomy may be required. ENT specialist should be consulted. Tympanocentesis or sterile culture technique of drainage from perforated TM (if present) should be prioritized to direct appropriate antimicrobial therapy.
Intracranial complications may occur and if clinically suspected (e.g headache, cranial nerve involvement, vertigo, nuchal rigidity,etc.), should be treated as presumptive meningitis until further information is obtained.
Acute mastoiditis (click for details)
Conversely, chronic mastoiditis is the result of chronic suppurative otitis media (painless otorrhea, greater than 3 weeks duration, patient rarely febrile) and hence there is communication from the external ear canal to the middle ear and the mastoid.
Hence, the pathogens are mainly S. aureus, Pseudomonas or other gram negatives. Fluid from ear drainage should be taken in a sterile fashion near TM and sent for aerobic, anaerobic, and fungal cultures initially as this is critical for targeting subsequent antimicrobial therapy.
Chronic mastoiditis (click for details)