Definition/Introduction

Clinicians perform an otoscope exam to assess the condition of the external auditory canal (EAC), tympanic membrane (TM), and the middle ear.  Steps of the otoscope exam include inspecting the EAC and the TM with its identifying landmarks as outlined below. A pneumatic attachment is available to apply pressure to assess the mobility (i.e., compliance) of the tympanic membrane. Mastering the otoscope exam leads to accurate diagnoses, allowing for targeted treatment and prevention of complications. Early stages of otologic diseases can be present in the absence of complaints such as ear pain, ear fullness, and hearing loss; therefore, the otoscope should be part of all routine exams performed by primary care clinicians and not specific to otolaryngologists.[1][2][3]

Issues of Concern

Technique

To inspect the right ear, the examiner holds the otoscope with their right hand and the ear with his left. The otoscope is held with three fingers, like a pen, between the thumb, first, and second fingers. The fifth finger rests on the patient's head to stabilize the otoscope. The EAC travels in a “sigmoid” fashion; therefore, the recommendation is to manipulate the pinna to allow for proper visualization of the TM. For adults and older children, the pinna is gently retracted in a posterior and cephalad vector. For neonates, the examiner pulls the pinna posteriorly and inferiorly. It is essential to use a fully charged otoscope, as low light may produce a yellow tint on the TM, which is subject to misinterpretation as middle ear effusion.[4][3][5]

External Auditory Canal (EAC)

Examiners inspect the EAC for cerumen impaction, foreign objects, canal edema, erythema, and otorrhea.

Tympanic Membrane (TM) and Middle Ear

The TM separates the external ear from the middle ear. When inspecting the TM, the examiner takes note of color, bulging, perforation, and the presence or absence of normal landmarks. The cone of light, handle of malleus, umbo, pars tensa, and pars flaccida make up the normal landmarks. The cone of light originates at the umbo and extends anteriorly (this allows the viewer to determine a right from left ear based solely on an otoscopic view). The TM is normally gray-colored, and its translucency allows for visualization of the incus and stapes, though the degree of translucency can vary from patient to patient.[5][6][7]

Pneumatic Otoscopy

Pneumatic otoscopy helps determine the mobility of the TM. With an adequate seal, air enters the EAC and increases pressure. A normal TM will respond by concaving into the middle ear cavity. The most common cause of decreased TM mobility is middle ear effusion. Therefore, pneumatic otoscopy aids in the diagnosis of acute otitis media (AOM) and otitis media with effusion (OME). Recent clinical practice guidelines report that AOM should not receive a diagnosis without evidence of middle ear effusion shown by pneumatic otoscopy. Other causes of decreased TM mobility are tympanosclerosis, TM retraction, and TM perforation.[8][9][10][11][12][13]

Clinical Significance

Cerumen Impaction

Cerumen impaction refers to a buildup of cerumen that causes symptoms such as hearing loss, ear fullness, itching, otalgia, tinnitus, cough, or rarely imbalance. In the presence of any of these symptoms, removal is indicated. The diagnosis of cerumen impaction can be made by direct visualization through an otoscope. Cerumen removal should occur if the examiner cannot visualize the entire TM. There are three options for intervention: irrigation, cerumenolytic agents, manual removal. If multiple attempts of removal are unsuccessful, referral to an otolaryngologist is warranted.[14][3][15]

Acute Otitis Media (AOM)

AOM is defined as an infection of fluid accumulated in the middle ear. It is primarily a pediatric diagnosis since most cases occur in patients 6 to 24 months of age, and decrease with advancing age so long as the patient has normal palatal muscle function. The most reliable symptom seen in AOM patients is otalgia, and up to two-thirds of patients present with fever. However, patients, especially children, can present with non-specific symptoms such as tugging on the affected ear, irritability, headache, poor sleep, poor feeding, vomiting, and diarrhea. Otoscopic examination is indicated with all children presenting with upper respiratory infection symptoms.[16][17]

In the context of the above symptoms, otoscopic findings help diagnose AOM. If necessary, cerumen should be removed to visualize the TM fully. The examiner evaluates the position, translucency, color, and mobility of the TM. AOM is associated with a bulging, opaque, erythematous, and immobile TM. The bulging and erythematous TM is the essential otoscopic finding used to distinguish AOM from otitis media with effusion (OME).

The preferred treatment for AOM is high dose amoxicillin, though amoxicillin/clavulanate is an option if the patient has taken amoxicillin within the last 30 days or has shown no improvement after 2 to 3 days of amoxicillin treatment. Oral cephalosporins, such as cefuroxime or cefdinir, are given for patients with a penicillin allergy. If these patients show no improvement after 2 to 3 days, the patient can receive intramuscular or intravenous ceftriaxone or clindamycin. Azithromycin and trimethoprim/sulfamethoxazole are associated with high rates of resistance and, therefore, should be avoided. Accurate diagnosis and avoidance of unnecessary antibiotic treatment are critical to prevent resistance to current first-line treatments. Tympanostomy tube placement is the preferred treatment for recurrent AOM.[18][14][19][20][21]

Otitis Media with Effusion (OME)

OME is defined as accumulated fluid in the middle ear space without evidence of inflammation or infection. OME is a common pediatric presentation, with an incidence of 20% in children. The combination of clinical signs and findings on the otoscope exam gives the diagnosis. The most common presenting symptoms are ear fullness and conductive hearing loss. On the otoscope exam, the TM will look opacified with a loss of a light reflex. Retraction of TM and decreased mobility are also common findings. Unlike in AOM, bulging of the TM is not typical. Most cases of OME are self-limiting. Antibiotics, oral decongestants, or intranasal corticosteroids are not effective treatment options.[22][23][24][21]

Otitis Externa (OE) and Malignant Otitis Externa (MOE)

OE is defined as an infection or inflammation of the ear canal. It has a 10% lifetime prevalence, 90% of cases are unilateral, and the majority of cases are in adults. There is a strong association with high humidity, higher temperature, swimming, local trauma to the ear canal, hearing aid use, and history of diabetes mellitus. The hallmark symptom is otalgia, primarily associated with pinna manipulation. Pruritus is a common precursor symptom. Patients also complain of ear fullness and hearing loss secondary to canal edema and debris accumulation. Otoscope findings include ear canal edema and erythema with thick seropurulent otorrhea, which can be malodorous. Audiologic testing can help rule out middle ear involvement.

Most cases of otitis externa are bacterial in origin; however, approximately 10% of cases are due to fungal pathogens. In these cases, whitish studs (Candida spp.) or small black “fungal balls” (Aspergillus spp.) are present. Treatment of uncomplicated OE includes clearing the EAC, topical antimicrobials, and adequate pain control. Oral antibiotics should start in patients with poorly controlled diabetes mellitus or immunosuppression.[25][26][27]

MOE, severe sequelae of OE, is an invasive infection of the EAC and skull base. Early diagnosis is critical; therefore, MOE should be a consideration with any patient with refractory OE, fever above 39 C, diabetes mellitus, or immunosuppression. On the otoscope exam, granulation tissue is visible along the floor of the EAC at the bony-cartilaginous junction (i.e., isthmus). Cranial nerve exams are warranted when evaluating for MOE. Spread to the stylomastoid foramen can present with facial nerve palsy. Spread to the jugular foramen can present with glossopharyngeal, vagus, or accessory nerve palsies. MRI and CT (without contrast) scans are useful in diagnosis, with CT being more sensitive for bone erosion. The mainstay treatment for MOE is culture-sensitive long-term antibiotic therapy, and in some cases, surgical debridement.[27][28][29]

Cholesteatoma

Cholesteatomas are defined as an abnormal collection of keratinized squamous epithelium, usually involving the middle ear and mastoid. Cholesteatomas can either be acquired or congenital. They progress slowly, and the clinical presentation is usually insidious. The most common early signs are conductive hearing loss and painless otorrhea. Granulation tissue or polyps seen in the ear canal are concerning for a cholesteatoma until proven otherwise. Cholesteatomas get treated surgically, and early detection depends on an accurate otoscope exam and can lead to less invasive surgical repair and preservation of hearing. In addition to clinical symptoms and otoscope exam, high-resolution CT and diffusion-weighted MRI assist in the diagnosis. The fusion of these imaging modalities provides a precise location of cholesteatoma, which aids in surgical planning.

Acquired cholesteatomas present with recurrent painless, malodorous otorrhea. A retraction pocket in the posterosuperior quadrant of the TM is the hallmark finding. Congenital cholesteatomas more often present asymptomatically compared to acquired cholesteatomas. As they grow, they can decrease hearing by middle ear bone chain erosion or mass effect. Due to the transparency of a normal TM, congenital cholesteatomas are visible during an otoscope exam.[30][31][32][22][33][34]

Tympanic Membrane Perforation (TMP)

Direct trauma, infection, pressure changes, or a tumor causes a TMP. Patients typically present with otalgia, otorrhea (may be bloody), tinnitus, or hearing loss. Perforations should be easily visible using an otoscope. The suggestion is that fogging of the otoscope indicates the presence of a perforation. After identifying a perforation on an otoscope exam, it is critical to determine if an urgent Otolaryngology consult is warranted. This is the case with vertigo, sensorineural hearing loss, severe tinnitus, active and severe bleeding, or facial paralysis. A superoposterior perforation should prompt a cholesteatoma evaluation.

Most cases of TMPs resolve spontaneously. Physicians should make sure the pain is adequately controlled and advise the patient to keep the affected ear dry. Otic drops should be avoided unless there is a concomitant infection. Surgical intervention, via tympanoplasty, should be considered for severe cases when spontaneous healing is unlikely.[7][35][13]

Nursing, Allied Health, and Interprofessional Team Interventions

The otoscope exam helps to assess the condition of the external auditory canal (EAC), tympanic membrane (TM), and the middle ear.  Mastering the otoscope exam leads to accurate diagnoses, allowing for targeted treatment and prevention of complications. Early stages of otologic diseases can be present in the absence of complaints such as ear pain, ear fullness, and hearing loss.

A quarter of adult and one-half of pediatric general practice consultations are related to ears, nose, and throat (ENT) complaints. In the emergency department, up to two-thirds of pediatric visits are relevant to the ear, nose, and throat. Lastly, primary care physicians consistently recognize ENT as one of the most pertinent surgical subspecialties to their practice.[36] With that said, the otoscope exam represents a crucial examination skill that should be able to be performed skillfully by not only otolaryngologists but also primary care providers (pediatrics, family medicine, internal medicine, etc.) and emergency department physicians as well.  Also, audiologists play a vital role in the evaluation of patients presenting with suspected otologic pathology, and therefore must be skilled in performing and communicating otoscope exam findings with patients and physicians alike. 

Despite the recognized importance of performing an accurate otoscope exam, there are reports that current healthcare didactic programs offer limited exposure to otolaryngology, which often correlates into decreased comfort amongst students when performing the otoscope exam. This limited exposure to proper otoscopy training may negatively impact patient outcomes and ultimately create an inefficient utilization of health care resources.[37]

To combat this suspected inefficiency in the otoscopic exam, it is incumbent upon all healthcare professionals involved (e.g., physicians, nurse practitioners, nurses, audiologists, students) to narrow the knowledge gap that currently exists regarding the otologic examination. This education can be done in a matter of ways, starting with self-educating on how to perform a proper otologic exam. Indeed, several methods and resources are available to accomplish this, many of which have shown diagnostic accuracy improvement after its implementation.[38][39]

Improved knowledge of otoscopy will lead to better interprofessional communication among the relevant health professionals involved. Subsequently, these enhancements should allow for increased patient-centered care, improved outcomes, higher patient safety, and enhanced team performance. [Level 5]