Summary
Mastoiditis is an infection of the mastoid air cells that typically develops as a complication of acute otitis media (AOM) and most commonly occurs in children < 2 years of age. Clinical features of mastoiditis include otalgia and tender, erythematous postauricular swelling with lateral and forward displacement of the ear. Fever and otorrhea may be present. Diagnosis is clinical, but imaging is indicated in the case of diagnostic uncertainty, suspected intracranial complications, and/or failure to respond to initial treatment. Management involves intravenous antibiotics and symptomatic management; surgical options are based on the extent of infection. Complications include spread of the infection to nearby structures (e.g., the brain). Chronic mastoiditis, a subtype of mastoiditis with a more indolent course, can occur as a complication of chronic otitis media. Management includes antibiotics and sometimes surgery.
Epidemiology
Most commonly occurs in children < 2 years [1]
Epidemiological data refers to the US, unless otherwise specified.
Etiology
- Common pathogens [1][2]
- See also “Etiology of AOM.”
Pathophysiology
Infection spreads from the middle ear cavity into the mastoid, which is a closed bony compartment → collection of pus under tension and hyperemic resorption of the bony walls → destruction of the air cells (coalescent mastoiditis) → mastoid becomes a pus-filled cavity (empyema mastoid)
Clinical features
Signs and symptoms [1][3]
- Otalgia
- Tender, erythematous, and edematous mastoid
- Ear displaced laterally and forward
- Otorrhea
- Hearing loss
- Systemic symptoms (e.g., fever, fatigue, irritability)
- Features of complications of mastoiditis (e.g., facial nerve palsy) [3]
- Symptoms of AOM for > 2 weeks
- Obliteration of the retroauricular sulcus in advanced stages
Otoscopy
- Bulging and erythematous tympanic membrane
- Normal in 10% of affected individuals [3]
Suspect mastoiditis in patients with recent or persistent otitis media and erythema, swelling, pain behind the ear, and/or protrusion of the pinna. [4]
Chronic mastoiditis typically has mild symptoms and develops slowly; patients may be afebrile and clinically well. [5]
Diagnosis
Approach
- Diagnosis is primarily clinical. [1]
- Laboratory findings (e.g., CBC, inflammatory markers) are nonspecific. [1]
- Signs of sepsis: Obtain blood cultures. [1]
- Effusion or otorrhea: Consult otolaryngology for consideration of culture from the middle ear. [5]
- Order imaging if: [6]
- No symptom improvement after 48 hours of treatment
- Diagnostic uncertainty
- Suspected intracranial complication
- Planned surgical intervention
Imaging
-
CT scan of the temporal bone with contrast: initial imaging study : [1]
- Opacification of the mastoid air cells [1]
- Erosion of the air cell walls
- Pus in the mastoid cavity (areas of enhancement on CT)
-
MRI brain and temporal bone with contrast: Consider as initial modality in children due to lack of ionizing radiation. [1][7]
- More sensitive for intracranial infectious complications
- Characteristic findings include increased fluid signal intensity in mastoid air cells.
Interpret imaging in conjunction with clinical symptoms; some findings such (e.g., opacification of the mastoid air cells) are also visible in acute and chronic otitis media. [1]
Subtypes and variants
Chronic mastoiditis
- Definition: mastoiditis that is present for > 1 month [5]
-
Pathophysiology
- Usually occurs as a complication of chronic otitis media
- Granulomatous tissue invades the mastoid air cells. [3]
-
Etiology [2][3]
- Often a mixed infection
- Pathogens include:
-
Clinical features: Features are milder and develop more slowly than in acute mastoiditis. [5]
- Mucopurulent otorrhea (intermittent or chronic) is common.
- Hearing loss and ear pain may occur.
- Postauricular swelling and fever may be absent.
- Symptoms are often mild; first presentation may be with complications of mastoiditis.
- Diagnostics: See “Diagnostics of mastoiditis.”
-
Management [5]
- Discuss antibiotic choices with infectious diseases.
- Refer to otolaryngology for further management.
Management
This section covers the management of acute mastoiditis. For management of chronic infections, see “Chronic mastoiditis.”
Approach [1]
- Unstable patients: Initiate immediate hemodynamic support.
- Start empiric IV antibiotic therapy.
- Provide symptomatic management (e.g., antipyretics, oral analgesia).
- Assess for signs of complications (e.g., meningitis, cranial nerve involvement)
- Consult otolaryngology for consideration of surgery.
- Adjust antibiotics based on clinical response and culture results.
Empiric antibiotic therapy for acute mastoiditis [1][2]
- Patients without either chronic otitis media or recent antibiotic use
- Ampicillin/sulbactam (off-label) [1][2]
- OR ceftriaxone [1][2]
- Patients with chronic otitis media or recent antibiotic use
- Cefepime (off-label)
- OR levofloxacin (off-label)
- OR piperacillin/tazobactam (off-label) [1]
- Severe penicillin reaction: clindamycin
- Suspected MRSA: Add vancomycin .
- Treatment duration is usually 2–4 weeks based on extent of disease. [2]
- Transition to oral antibiotics when patients clinically improve. [2]
Surgery [1]
Surgical options include:
- Myringotomy with or without tympanostomy tube insertion
- Mastoidectomy: in severe or refractory mastoiditis (e.g., bone destruction)
- Incision and drainage
- Debridement
Complications
Untreated, the infection may spread through the bony walls and cause the following complications:
- Postauricular abscess
-
Bezold abscess
- Pus breaks the tip of the mastoid and dissects into the neck, often collecting behind the sternocleidomastoid.
- Causes neck pain, torticollis, and fever
- Treatment: IV antibiotics, mastoidectomy, and drainage of neck abscess
-
Zygomatic abscess
- Infection spreads to the zygomatic air cells (located at the zygomatic root)
- Causes swelling in front of and above the auricle
- Brain abscess: manifests as fever, focal neurological deficits, and signs of raised intracranial pressure
- Cranial nerve palsies: abducens nerve, facial nerve, and the ophthalmic branch of the trigeminal nerve
We list the most important complications. The selection is not exhaustive.