Mastoiditis

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Ogheneochuko Ajari, MB.BS, MS [2], Faizan Sheraz, M.D. [3]

Mastoiditis Microchapters
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Patient Information
Overview
Historical Perspective
Classification
Pathophysiology
Causes
Differentiating Mastoiditis from other Diseases
Epidemiology and Demographics
Risk Factors
Screening
Natural History, Complications and Prognosis
Diagnosis
History and Symptoms
Physical Examination
Laboratory Findings
X Ray
CT
MRI
Ultrasound
Other Imaging Findings
Other Diagnostic Studies
Treatment
Medical Therapy
Surgery
Primary Prevention
Secondary Prevention
Cost-Effectiveness of Therapy
Future or Investigational Therapies
Case Studies

Overview

Mastoiditis is the infection of mastoid ear cells in the process of temporal bone. It is mostly a complication of ear diseases such as Acute Otitis Media and chronic otitis media, and it tends to occur in children. However after developments of antibiotics acute otitis media complications have decreased significantly.

Symptoms and Signs

Some common symptoms and signs of mastoiditis include pain and tenderness in the mastoid region, as well as swelling. There may be ear pain (otalgia), and the ear or mastoid region may be red (erythematous). Fever or headaches may also be present. Infants usually show nonspecific symptoms, such as anorexia, diarrhea, or irritability. Drainage from the ear occurs in more serious cases.

Prognosis

With prompt treatment, it is possible to cure mastoiditis. Seeking medical care early is important. However, it is difficult for antibiotics to penetrate to the interior of the mastoid process and so it may not be easy to cure the infection; it also may recur. Mastoiditis has many possible complications, all connected to the infection spreading to surrounding structures. Hearing loss may result, or inflammation of the labyrinth of the inner ear (labyrinthitis) may occur, producing vertigo. The infection may also spread to the facial nerve (cranial nerve VII), causing facial-nerve palsy which can produce weakness or paralysis of some facial muscles on that side of the face. Other complications include Bezold's abscess, an abscess (a collection of pus surrounded by inflamed tissue) behind the sternocleidomastoid muscle in the neck, or a subperiosteal abscess, between the periosteum and mastoid bone ( resulting in the typical appearance of a protruding ear). Serious complications result if the infection spreads to the brain. These include meningitis (inflammation of the protective membranes surrounding the brain), epidural abscess (abscess between the skull and outer membrane of the brain), dural venous thrombophlebitis (inflammation of the venous structures of the brain), or brain abscess.

Diagnosis

The diagnosis of mastoiditis is clinical—based on the medical history and physical examination. Imaging studies may provide additional information; the study of choice is the CT scan, which may show focal destruction of the bone or signs of an abscess (a pocket of infection). X-rays are not as useful. If there is drainage, it is often sent for culture, although this will often be negative if the patient has begun taking antibiotics.

Treatment

The primary treatment for acute mastoiditis without osteitis is the administration of intravenous antibiotics after obtaining cultures. The choice of antimicrobial agents is similar to that for acute otitis media—antibiotics against Streptococcus pneumoniae and Haemophilus influenzae. Additional coverage for Staphylococcus aureus and Gram-negative bacilli may be considered for protracted disease until the results of cultures become available. Ciprofloxacin (500 mg twice a day) may be considered in immunocompromised patients with diabetes or HIV infection or in infections involving the skin and periauricular areas. Long-term antibiotics may be necessary to completely eradicate the infection. Otalgia associated with otitis externa may be managed with topical anesthesic agent such as benzocaine.

Mastoiditis

• 1. Acute Mastoiditis

• 1.1 Causative pathogens:

• Streptococcus pneumoniae
• Streptococcus pyogenes
• Staphylococcus aureus
• Hemophilus influenzae
• Pseudomonas aeruginosa

• 1.2 Acute mastoiditis, outpatient

• 1.2.1 Empiric antimicrobial therapy

• Preferred regimen (no abx in past month): Amoxicillin 50 mg/kg/day PO q6h
• Preferred regimen (abx in past month): Amoxicillin-Clavulanate 90 mg/kg/day PO q12h OR Cefdinir 14 mg/kg PO q24h OR Cefpodoxime 10 mg/kg/day PO q12h (maximum dose is 400 mg/day) OR Cefprozil 30 mg/kg/day PO q12h (maximum dose is 1 g/day) OR Cefuroxime 15 mg/kg/day PO q12h (Maximum dose is 1 g/day)
• Note: Duration of treatment in children <2 years-old is 10 days. In children ≥2 years, recommended duration is 5–7 days.

• 1.2.2 Pathogen-directed antimicrobial therapy

• 1.2.2.1 Staphylococcus aureus (MSSA)

• Preferred regimen: Oxacillin 37 mg/kg IV q6h (maximum dose is 8-12 g/day)

• 1.2.2.2 Staphylococcus aureus (MRSA)

• Preferred regimen: Vancomycin 40 mg/kg/day IV q6-8h
• Note: Maintain Vancomycin serum trough concentrations of 15-20 mcg/mL

• 1.3 Acute mastoiditis, inpatient

• 1.3.1 Empiric antimicrobial therapy

• Preferred regimen: Cefotaxime 1-2 g IV q4-8h OR Ceftriaxone 1 g IV q24h

• 1.3.2 Pathogen-directed antimicrobial therapy

• 1.3.2.1 Staphylococcus aureus (MSSA)

• Preferred regimen: Oxacillin 37 mg/kg IV q6h (maximum dose is 8-12 g/day)

• 1.3.2.2 Staphylococcus aureus (MRSA)

• Preferred regimen: Vancomycin 40 mg/kg/day IV q6-8h
• Note: Maintain Vancomycin serum trough concentrations of 15-20 mcg/mL

• 2. Chronic Mastoiditis

• 2.1 Causative pathogens:

• Polymicrobial
• Enterobacteriaceae
• Staphylococcus aureus
• Pseudomonas aeruginosa

• 2.2 Empiric antimicrobial therapy

• Preferred regimen: Imipenem 0.5 g IV q6h OR Piperacillin-Tazobactam 3.375 g IV q4-6h OR Meropenem 1 g IV q8h OR Ticarcillin-Clavulanate 3.1 g IV q6h
• Note: Treatment is reserved for acute exacerbations or perioperatively. It is recommended not to treat without surgical cultures

Surgery

If the condition does not respond to antibiotics or is associated with osteitis, surgical procedures may be performed while continuing the medication. The most common procedure is myringotomy with tympanostomy tube placement for drainage and culture of effusion. When an abscess has formed in the mastoid bone, a mastoidectomy should be performed after antimicrobial agents have controlled sepsis.

Prevention

In general, mastoiditis is rather simple to prevent. If the patient with an ear infection seeks treatment promptly and receives complete treatment, the antibiotics will usually cure the infection and prevent its spread. For this reason, mastoiditis is rare in developed countries.

Gallery

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  Picture of a right mastoidectomy, surgeon's view. Note the blue color of the skeletonized sigmoid sinus.

• 

  Picture of a left mastoidectomy, surgeon's view.

• 

  In this left canal wall up mastoidectomy, the tympanic membrane has been elevated forward and a cholesteatoma sac is visible in the attic.

• 

  This patient has a recurrent cholesteatoma which has found its way to the surface of the post-auricular skin, forming a mastoid cutaneous fistula.

• 

  This cholesteatoma sac has eroded the lateral surface of the mastoid bone and was found immediately under the post-auricular skin.

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  Left canal wall down mastoidectomy.This patient had a modified radical mastoidectomy with tympanoplasty. The posterior bony canal has been removed and part of the dry "mastoid bowl" is visible posterior and superior to the reconstructed tympanic membrane .

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  Magnification of the previous picture .

Further Reading

• Durand, Marlene & Joseph, Michael. (2001). Infections of the Upper Respiratory Tract. In Eugene Braunwald, Anthony S. Fauci, Dennis L. Kasper, Stephen L. Hauser, Dan L. Longo, & J. Larry Jameson (Eds.), Harrison's Principles of Internal Medicine (15th Edition), p. 191. New York: McGraw-Hill
• "Mastoiditis" (July 30, 2003). MedlinePlus Medical Encyclopedia.