Otitis media (OM) is primarily a disease of infancy and childhood (see chapter 118 for management of OM in children). While the management of OM in children and adults is similar, there are important differences in adults, highlighted below, especially for the management of OM with effusion.
PATHOPHYSIOLOGY AND MICROBIOLOGY
Viral upper respiratory tract infections precede or coincide with 70% of acute OM cases.17 The most common associated viral pathogens are respiratory syncytial virus, adenovirus, and cytomegalovirus.18 The most common bacterial pathogens recovered in acute OM are Streptococcus pneumoniae (43% to 49%), nontypable Haemophilus influenzae (29% to 70%), and Moraxella catarrhalis (15% to 28%).17,19 The H. influenzae type b vaccine has no effect on nontypable H. influenzae. Most adults have never received this vaccine and thus remain unprotected from all Haemophilus flu strains. The predominant organisms involved in chronic OM are S. aureus (35%), P. aeruginosa (22%), Aspergillus (13%), and less commonly, anaerobic bacteria.20 OM with effusion is differentiated from acute OM. In adults, OM with effusion is frequently associated with significant pathology: acute or chronic sinusitis in 66%, smoking-induced nasopharyngeal lymphoid hyperplasia and adult-onset adenoidal hypertrophy in 19% of cases, and head and neck tumors (mainly nasopharyngeal carcinomas) in 4.8%.21 Adult patient with OM with effusion may also have symptoms of gastroesophageal reflux.22
CLINICAL FEATURES AND DIAGNOSIS
The typical ED presentation is a prodrome of an upper respiratory tract infection followed by sudden increase in otalgia, with or without fever. Otorrhea and hearing loss are variably present, while tinnitus, vertigo, and nystagmus are uncommon but possible findings. Diagnosis is clinical. The TM may be retracted or bulging. It may be red in color, indicating inflammation, or it may be yellow or white, as a result of middle-ear fluid. Pneumatic otoscopy almost uniformly demonstrates impaired mobility. Pain and new otorrhea (in the absence of external otitis) helps to confirm the diagnosis. Always assess facial nerve function because of the nerve's proximity to the middle ear. Guidelines are available for the diagnosis and management of OM in children,23 but none have been published for adults. In adults, OM with effusion presents with ear discomfort or fullness or may present with decreased hearing without discomfort. OM with effusion is diagnosed based on physical exam findings of middle-ear effusion with little inflammatory changes, including pneumatic otoscopy showing an immobile TM. In adults, there will typically be other physical exam findings such as sinusitis or enlarged adenoids behind the uvula. Coexistent symptoms of reflux should be elicited.
There are no treatment guidelines specifically for adults. The "wait-and-see" method recommended in children24 has not been evaluated in adults. The preferred adult initial treatment is amoxicillin.11 The dose in adults (weighing >40 kg) is 875 or 1000 milligrams every 12 hours, or 500 milligrams every 8 hours, for 7 to 10 days. Alternative agents include amoxicillin-clavulanate, cefdinir, or cefpodoxime. For OM unresponsive to initial therapy after 72 hours, consider changing to amoxicillin-clavulanate, levofloxacin, or moxifloxacin.
Provide pain control with acetaminophen or ibuprofen or with narcotics for severe pain. Topical agents such as antipyrine/benzocaine otic may also be given.25 OM with effusion requires treatment with the same antimicrobials, but for 3 weeks, and prednisone may be added at follow-up. Patients with OM with effusion and coexisting symptoms of reflux should be treated with appropriate antireflux medications (see chapter 74, "Esophageal Emergencies").
Adults with OM should receive follow-up to assess treatment efficacy and to ensure that there is no anatomic obstruction to the eustachian tube, as, for example, from occult neoplasm. Any patient who presents with complications of OM or who appears septic should have urgent consultation for diagnostic and therapeutic tympanocentesis and admission for IV antibiotics.
COMPLICATIONS OF OTITIS MEDIA
Complications of OM are intratemporal and intracranial. Perforation of the TM is a common intratemporal complication and most often occurs in the pars tensa from the increased pressure of middle-ear secretions, with resultant otorrhea. Healing usually occurs in 1 week, although a chronic perforation may result. A temporary conductive hearing loss may occur from fluid in the middle ear. Hearing loss should resolve as the fluid is resorbed. Acute serous labyrinthitis may occur when bacterial toxins enter the inner ear through the round window. Facial nerve paralysis is an uncommon complication but requires emergent otolaryngology consultation.
Acute Mastoiditis and Cholesteatoma
Acute mastoiditis results from spread of infection from the middle ear to the mastoid air cells by the aditus ad antrum. When this opening becomes blocked, the mastoid cavity becomes a closed space, and the mastoid air cells become inflamed and fill with fluid. The most common pathogens are S. pneumoniae (38%), Streptococcus pyogenes (11%), and P. aeruginosa (11%).26 In addition to otalgia, fever, and otorrhea (especially in patient with Pseudomonas), patients with mastoiditis will have postauricular erythema, swelling, and tenderness, with protrusion of the auricle and obliteration of the postauricular crease. Diagnosis is suspected based on the history and physical examination and confirmed on IV contrast CT scan. Mastoiditis requires admission for IV antibiotics, tympanocentesis, and myringotomy. For first episode, treat with ceftriaxone, 1 gram IV every 24 hours, or levofloxacin, 750 milligrams every 24 hours.13 For recurrent episodes, treat with vancomycin, 1000 milligrams IV, and piperacillin-tazobactam, 3.375 gram initial dose IV, or imipenem. Incision and drainage of subperiosteal abscess or mastoidectomy may ultimately be required.
Aural cholesteatomas are collections of epidermis and exfoliated keratin within the middle ear or mastoid. As the cholesteatoma expands, it may erode the ossicular chain, bony labyrinth, or facial nerve canal. Cholesteatomas are often infected, and their intracranial extensions may be life threatening. Treatment requires otolaryngolic evaluation.
Intracranial complications of OM are more likely with chronic than with acute OM and are, in general, decreasing with the widespread use of antibiotics in the treatment of OM. However, suppurative intracranial extension is a severe complication, and suggestive signs and symptoms should be investigated appropriately. Meningitis and brain abscess are the most common intracranial complication of OM with an incidence of 0.42 per 100,000 per year.27 The most prevalent causative organisms are S. pneumoniae (33%) and Neisseria meningitidis (23%).27 Extradural abscess and subdural empyema are also potential complications.
Lateral sinus thrombosis is another ominous complication of acute OM. It arises from extension of infection and inflammation in the mastoid, with eventual inflammation of the adjacent lateral or sigmoid sinus. Reactive thrombophlebitis with mural clot formation, intraluminal empyema, or perforation of the venous wall may occur.
Headache is the most common symptom, with papilledema, sixth-nerve palsy, and vertigo being less frequently present. Angiography with venous phase and MRI are more sensitive than CT in diagnosing lateral sinus thrombosis. The employed antibiotic regimen should cover Staphylococcus, Streptococcus, and upper respiratory anaerobes, and have good penetration of the blood–brain barrier. A combination of IV penicillin or nafcillin, ceftriaxone, and metronidazole is one initial empiric regimen.28