History

Before the advent of antibiotics, mastoiditis was a frequent complication of otitis media that could be treated only by expectant waiting or surgery. The first surgical opening of the mastoid cavity was performed in 1736 by Petit using a trepanation system. The trepanation system gave way to the chisel and gouge, which was then replaced by the electric drill, which was introduced at the end of the 19th century. When surgery was used, many patients with mastoiditis were cured by simple mastoid drainage alone, with a mortality rate quoted at 2%. Intracranial complications of mastoiditis carried a very grave prognosis, however. In the preantibiotic era between 1928 and 1933, 25 of every 1000 deaths at Los Angeles County Hospital in California were caused by intracranial complications of otitis media, such as meningitis, venous sinus thrombosis, and brain abscess. In contrast, between 1949 and 1954, only 2.5 per 1000 deaths at the same hospital were caused by complications of otitis or mastoiditis. The use of antibiotics in treating mastoiditis initially led to a marked decrease in the surgical approach to treatment of this illness. The realization that infection can persist and that complications of mastoiditis can occur even while the patient is receiving antibiotic therapy has resulted in the present-day approach of combined antibiotics and surgery, necessitating collaboration between the pediatrician and otolaryngologist.

Anatomy and Pathophysiology

The mastoid process comprises the posterior part of the temporal bone and, as such, is adjacent to many important structures. Within the mastoid is an interconnecting system of air cells divided by bony septa that drain anteriorly into the epitympanic recess of the middle ear via a narrow aditus. Only the superior portion of the mastoid airspace, the antrum, is present at birth; pneumatization of the mastoid starts soon after birth and usually is completed by the time the child is 2 years of age. Structures lying anteromedial to the mastoid process include the middle ear and ossicles, the facial nerve, the posterior bony wall of the external auditory canal, the jugular vein, and the internal carotid artery. Posteromedially, the mastoid borders the posterior cranial fossa and the sigmoidal sinus. Superiorly, the mastoid borders the middle cranial fossa. Medially, the mastoid cortex encases the cochlea and semicircular canals. The soft tissues and muscles of the lateral neck are located inferiorly. Any or all of these adjacent structures can be affected by extension of a suppurative process in the mastoid.

A certain amount of mastoid inflammation accompanies all cases of otitis media because the mastoid airspaces are continuous with the middle ear cavity, and both are lined by a continuous mucoperiosteum. The first stage of an ear and mastoid infection is associated with hyperemia of the middle ear and the mastoid air cell mucosa. If the infection persists, an exudative stage develops, with serum, fibrin, polymorphonuclear cells, and red blood cells accumulating in the middle ear and mastoid. The accumulation of purulent exudate increases the middle ear pressure, eventually resulting in perforation of the tympanic membrane, followed by drainage of mucopurulent matter from the middle ear and mastoid air cells. Some children also have such marked mucoperiosteal swelling that the drainage of pus from the mastoid is blocked, causing aditus blockade. The pus under pressure creates an environment of local acidosis, hypoxia, and ischemia, causing decalcification and resorption of the bony septa. The term coalescent mastoiditis is applied to this process because, with the destruction of the bony septa, the mastoid air cells coalesce into large cavities. Osteomyelitis of the adjacent bone may develop, with subsequent bony erosion and eventual extension of the infection into surrounding structures.

Congenital cholesteatomas usually manifest as a “squamous pearl” in the anterosuperior quadrant of the middle ear, abutting the tympanic membrane. They may be associated with recurrent otitis media. Acquired cholesteatomas often are a result of chronic infections and tympanic membrane perforation. The perforation allows for squamous material from the external auditory canal to enter the middle ear space (medial migration or Habermann’s theory). This tissue contains osteolytic enzymes, leading to bony erosion or mastoid air cell obstruction. Cholesteatomas also may cause slow, insidious erosion of underlying bone, predisposing the patient to extramastoid spread of infection months or years later.

Microbiology

The bacteriologic findings in 12 studies of acute mastoiditis and one study of chronic mastoiditis are presented in Table 17.1 . These studies, which were all carried out in the antibiotic era, span a 61-year time period and occurred in seven countries. *

* References .

† References .

Other organisms of importance in acute mastoiditis are Staphylococcus aureus, Haemophilus influenzae, and Pseudomonas aeruginosa. Because nontypable H. influenzae is a very common cause of otitis media, it is surprising that this agent is not more commonly recovered in acute mastoiditis. Similarly, Moraxella catarrhalis , another common cause of otitis media, is rarely found in association with acute mastoiditis.

Also, because neither S. aureus nor P. aeruginosa is a cause of acute otitis media it is likely that these agents, when isolated in acute mastoiditis, are secondary rather than primary pathogens. The same is likely for coagulase-negative staphylococci and various anaerobic organisms. However, in contrast to S. aureus and P. aeruginosa, if coagulase-negative staphylococci and anaerobic organisms are present they may be contaminates and may not contribute to the infectious process.

An increased incidence of penicillin-resistant S. pneumoniae infections has occurred during the past 25 years, leading to a higher likelihood of mastoiditis being a complication of otitis media. The percentage of pneumococcal mastoiditis caused by penicillin-resistant strains increased from 25% to 44% between 1994 and 1998, without an increase in the total number of cases of pneumococcal mastoiditis. Pneumococcal conjugate vaccine (PCV7) was introduced into the pediatric immunization schedule in 2000 and, over the ensuing decade, invasive pneumococcal disease decreased dramatically (see Chapter 85 ). PCV7 contains the serotypes 14, 6B, 19F, 18C, 23F, 4, and 9V. Surprisingly, in a large study performed by Choi and Lander, the number of admissions for mastoiditis at an urban tertiary care children’s hospital did not decrease in the PCV7 vaccine era. In fact, the post-PCV7 patients had more severe disease compared with patients seen between 1996 and 2002.

Ongkasuwan and associates studied 41 cases of pneumococcal mastoiditis between 1995 and 2007. In the pre-PCV7 era (1995–99) there were 12 cases, and none was caused by the nonvaccine serotype 19A. Between April 2000 and October 2005, there were 15 cases of pneumococcal mastoiditis, and 5 of these cases were due to pneumococcal serotype 19A. In their last time period (November 2006 to June 2007), there were 14 cases, and all were due to serotype 19A. Sixty-eight percent of the serotype 19A isolates had multidrug antibiotic resistance.

In the post-PCV7 era, Giannakopoulos and associates noted that nonvaccine genotype 19A was found in more than half of their mastoiditis cases. In Colorado, Halgrimson and colleagues noted a significant decline in acute mastoiditis cases after the introduction of PCV7. This decline was short-lived, however, with a return to pre-PCV7 rates. In Israel, Amir and coworkers noted an increase of acute mastoiditis caused by S. pyogenes between the early 1990s and 2003–09. In another study in Israel, it was noted that there was no overall reduction in acute mastoiditis or in pneumococcal acute mastoiditis in the era of pneumococcal conjugate vaccines. PCV13, the 13-valent pneumococcal conjugate vaccine, was introduced in 2010. Most recently, Tawfik and colleagues used cross-sectional data from the Healthcare Cost and Utilization Project Kids’ Inpatient Database to look at the annual prevalence of hospital admission for acute otitis media and its associated complications (acute mastoiditis, suppurative labyrinthitis, or acute petrositis) for the years 2000, 2003, 2006, 2009, and 2012. They found a significant reduction in the national prevalence rates of hospital admission for acute otitis media and its associated complications for all children younger than 21 years from 3.956 to 2.618 per 100,000 persons. The most significant declines were seen between 2000 and 2003 and between 2009 and 2012.

In 2013, Yarden-Bilavsky and associates noted seven cases of acute mastoiditis due to Fusobacterium necrophorum . The illnesses in these seven young children were quite fulminate and resulted in prolonged hospitalizations.

The bacteriologic spectrum of chronic mastoiditis differs from that of acute mastoiditis. Aerobic cultures of chronic mastoiditis and chronic otitis media show predominantly S. aureus and gram-negative bacilli, especially P. aeruginosa . In addition, a wide variety of anaerobic organisms can be isolated from an infected mastoid and middle ear. Brook studied the aerobic and anaerobic bacteriology of chronic otitis media (of ≥3 months’ duration) in 24 children. Anaerobic isolates alone were found in 17%, aerobic organisms alone were found in 4%, and mixed aerobic and anaerobic infections were found in 79%. All cases had from two to seven different bacterial isolates. Peptococcus spp., Actinomyces spp., and Bacteroides melaninogenicus ( Prevotella melaninogenica ) were the most commonly isolated anaerobic organisms. Seventeen patients were infected with β-lactamase–producing organisms (i.e., S. aureus or P. melaninogenica, Bacteroides fragilis, or other Bacteroides spp. that were resistant to ampicillin).

Mycobacterium tuberculosis currently is an uncommon cause of mastoiditis in the United States but continues to be a cause of chronically draining ears in lower socioeconomic groups and immigrants from endemic areas. Case reports of mastoiditis implicate such organisms as nontuberculous mycobacteria, Turicella otitidis, Aspergillus fumigatus Paragonimus -like trematodes, Nocardia asteroides, Actinomyces spp., Blastomyces dermatitidis , and Histoplasma capsulatum. Pneumocystis jiroveci otitis media and mastoiditis have occurred as the first manifestation of acquired immunodeficiency syndrome.

Clinical Presentation

The classic presentation of acute mastoiditis is a febrile child with ear pain, postauricular swelling, and postauricular tenderness developing days to weeks after the beginning of development of acute otitis media ( Fig. 17.1 ). If antibiotics were used to treat acute otitis media, the child may have seemed to improve only to become ill again while still receiving therapy or after the antibiotics were stopped; conversely, the inflammation may not have responded to the antibiotics at all. Examination of the tympanic membrane in acute mastoiditis usually shows that it is abnormal. Early in the course of illness, periosteal inflammation produces swelling and tenderness and sometimes redness over the mastoid process. Palpable postauricular fluctuance occurs later, when pus from the mastoid air cells breaks through the underlying bony cortex and forms a subperiosteal abscess. In children older than 1 year of age, the most common area where fluctuance is felt lies behind the ear, where it pushes the earlobe up and out; however, in children younger than 1 year, the fluctuance often may occur above the ear, pushing the pinna down and out.

An 18-month-old child with right-sided mastoiditis and proptotic right auricle.

Mastoiditis has occurred in children with cochlear implants. Zawawi and colleagues reviewed all publications and noted 43 children who had cochlear implants and who subsequently developed acute mastoiditis. They observed that with proper treatment (intravenous antimicrobials and surgery) the implants did not need to be removed in all but one instance.

Chronic mastoiditis is a much more indolent disease process than acute mastoiditis. It develops when long-standing middle ear disease, usually having a duration of months to years, has been present. Fever and postauricular swelling may or may not be present. Persistent or intermittent drainage of mucopurulent matter from a previously perforated eardrum suggests chronic mastoiditis. Hearing loss and ear pain also may accompany chronic mastoiditis. All these symptoms can be mild enough to be ignored until serious intracranial suppuration occurs. Persistent ear drainage, persistent ear pain, or an otitis media nonresponsive to antibiotics should prompt a search for mastoiditis.

Complications

Complications of mastoiditis include subperiosteal abscess, Bezold abscess, facial nerve paralysis, meningitis, brain abscess, cerebellar abscess, epidural abscess, subdural empyema, labyrinthitis, venous sinus thrombophlebitis, bacteremia, benign intracranial hypertension, osteomyelitis of the temporal bone with occasional extension to adjacent bones, hearing loss, septic pulmonary emboli, and cerebrospinal fluid otorrhea. Subperiosteal abscesses appear as a postauricular fluctuant mass that obscures the postauricular sulcus. They occur when pus in the mastoid breaks through the bony cortex or extends along vascular channels and dissects under the overlying periosteum.

A Bezold abscess develops when a mastoid infection erodes through the bony cortex of the inferior aspect of the mastoid tip and dissects down the tissue planes to form a deep neck abscess. Fluctuance over the mastoid is not felt. Rather, swelling and tenderness are present below the mastoid process and under the sternocleidomastoid muscle.

The facial nerve runs through the mastoid and the middle ear, rendering it vulnerable to injury when extension of mastoid or middle ear infection occurs. Pressure on and inflammation of the facial nerve from symptomatic or asymptomatic mastoiditis can lead to transient or permanent facial nerve paralysis that usually is unilateral, although bilateral facial palsy from mastoiditis can occur.

Because the temporal bone that houses the mastoid air cells constitutes the floor of the middle and posterior cranial fossae, bony erosion from osteomyelitis, preexisting bony defects, or spread of infection along vascular channels can allow for intracranial spread of mastoid infections into the middle and posterior cranial fossae. The infection may remain confined to the extradural space as an extradural abscess, or it may penetrate the dura and produce a subdural empyema, a brain abscess, a cerebellar abscess, or meningitis.

Invasion of infection into the bony labyrinth through the oval or round window triggers labyrinthitis. Initial tinnitus, hearing loss, nausea, and dizziness progress to severe vertigo, ear pain, vomiting, nystagmus, and difficulties with balance.

Intracranial venous sinus thrombophlebitis is a rare but potentially fatal complication of mastoiditis. *

* References .

Benign intracranial hypertension can be seen in association with lateral sinus obstruction involving the torcular and sagittal sinus secondary to mastoiditis and is termed otitic hydrocephalus. Rarely otitic hydrocephalus can be seen with mastoiditis in the absence of lateral sinus thrombosis. The decreased venous drainage caused by the venous sinus obstruction results in increased intracranial pressure, headache, papilledema, and sixth nerve palsy without enlarged ventricles or a space-occupying lesion.

Permanent conductive hearing loss occurs when the middle ear mastoid infection is severe enough to damage or destroy the ossicles. Tuberculous mastoiditis classically manifests as marked conductive hearing loss that often is irreversible.

Osteomyelitis secondary to mastoiditis can spread to adjacent bones. Involvement of the petrous portion of the temporal bone produces a syndrome, described by Gradenigo in 1907, with a triad of abducens paralysis or paresis, severe pain in the distribution of the trigeminal nerve, and suppurative otitis media; this is known as Gradenigo’s syndrome or petrous apicitis, and additional cranial nerve deficits also may occur. Antibiotics may mask the classic signs of petrositis and allow progression to severe intracranial complications, such as meningitis and epidural abscess. Petrositis may be suspected only when antibiotic and surgical management for mastoiditis fails to control chronic ear drainage.

M. tuberculosis mastoiditis is an uncommon finding but should be considered in children who have chronic ear discharge despite having received antibiotic therapy. Children can go for months or years with chronically draining ears before the diagnosis of tuberculous mastoiditis is considered. Children from lower socioeconomic homes, immigrants from endemic areas, and children with tuberculosis contacts in the family are at risk. The classic presentation in the preantibiotic era was an afebrile young child with painless persistent watery ear drainage, an enlarged preauricular lymph node, a history of contact with a person with tuberculosis, and often facial nerve paralysis.

Tuberculous mastoiditis is not always painless. Sometimes the diagnosis initially is suspected only when a mastoidectomy wound does not heal. Early in the course of the disease, physical examination may reveal small yellow spots (caseating granulomas) on a thickened and hyperemic tympanic membrane. These spots coalesce early and produce multifocal tympanic membrane perforations. The discharge through these perforations initially is watery, but later it becomes purulent. Pale, avascular granulation tissue is abundant throughout the middle ear and mastoid and often is seen in the external auditory canal and around the tympanic membrane perforation. Preauricular and postauricular nontender, enlarged lymph nodes may be present, and early and severe hearing loss is characteristic. Often, there is evidence of tuberculosis elsewhere in the body. A tuberculin skin test usually, but not always, is positive.