The Ear
Nature, I am persuaded, did not without a purpose frame our ears open, putting thereto no gate at all, nor shutting them up with any manner of inclosures, as she hath done upon the tongue, the eyes, and other such out-jetting parts of the body. The cause as I imagine, is, to the end that every day and every night, and that continually, we may be ready to hear, and by a perpetual hearing apt to learn. For, of all the senses, it is the fittest for the reception of the knowledge of arts, sciences, and disciplines.
—RABELAIS, GARGANTUA AND PANTAGRUEL, III, 16
POINTS TO REMEMBER:
Abnormalities of the external ear occur in many congenital conditions, especially renal abnormalities.
Note the position and shape of the pinna and examine the skin and the cartilage. Pay attention to the ear canal as well as to the tympanic membrane, including its entire periphery.
If you fail to screen for hearing impairment, you will miss a lot of important pathology. Never assume that you can rule out hearing loss by the “grossly intact” test.
External Inspection
It is best to examine the patient, with him sitting up, if possible, so that his ears are approximately at your eye level.
Deformities of the External Ear
Low-set ears have been referred to for decades as a sign of Down syndrome and other congenital anomalies (Fig. 11-1). Ears appear to be low set if the neck is short or extended, if the cranial vault is high, if the ramus of the mandible is short, or if the auricles are rotated. One definition of low-set ears is that they are completely beneath a coronal plane passing through the pupils and palpebral fissures. In neonates, this definition produces false positives. Measurements of the distance between the upper and lower attachments of the auricles and a bony landmark on the zygomatic process showed a wide variation in 1,000 apparently normal newborns (Oommen, 1997).
Deformities of the ear, including those of just the earlobe, are said to correlate with renal abnormalities, predicting the side(s) of the lesion. To demonstrate this, one needs a patient from whom an intravenous pyelogram has been obtained. As this is not a routine screening test, this clinical correlation is at least partly based on a biased sample, leading to an artifactually increased predictive value of a positive test. (In other words, no intravenous pyelogram would have been performed unless there had been some reason to suspect a renal problem.) Still, the correlation seems to be a useful one, although many of the anomalies are benign and asymptomatic, such as reduplication of the ureter on the side of the ear malformation.
Swelling of the skin of the anterior or external surface of the pinna with or without tenderness is a sign of subcutaneous hematoma or abscess. This is usually due to blunt trauma or traumatic twisting or bending of the pinna. Without immediate surgical intervention, the result would be “cauliflower ear,” which is caused by the dissolution of the cartilage and the formation of scar tissue. This abnormality was typical of people engaged in the sport of wrestling before protective head gear was used.
Earlobe Creases
Earlobe creases (also called Frank creases for their discoverer) are a risk factor1 for coronary artery disease (Elliott, 1983; Frank, 1973) (Fig. 11-2). As they may occur on only one side, be sure to look at both earlobes.
A study of 340 consecutive patients undergoing coronary arteriography has shown that the Frank sign, if present in either ear and extending for a distance greater than half the diagonal length of the earlobe, correlated with coronary artery disease, age, and arcus senilis (Pasternac and Sami, 1982). The sensitivity of the sign was 60%. (Review Chapter 1 and write down definitions for sensitivity, specificity, and positive predictive value on a piece of paper.) The specificity of the test was 82%. (Recall that specificity refers to the chance that a person who does not have the disease will not have the sign.) The positive predictive value of the sign was 91%. This suggests that the test is a fairly reliable one.
Dr A.I. Mendeloff of Maryland points out that 75% of the subjects (in this study) had coronary artery disease. That is, the study population had a very high prevalence of the disease in question, much higher than the prevalence that would be seen in a supposedly random population presenting at a physician’s office. As the prevalence of the disease would actually be much less in a nonselected population, would you expect a study of the Frank earlobe crease using the same criteria but a randomly selected population to produce a different result for sensitivity, specificity, or positive predictive value? Write down your answers at this point. (Hint: Ask yourself which items in the equations would be increased by diluting the numbers in the present study with persons who have no coronary artery disease.)
In a review of the world literature (Elliott, 1983) involving 6,414 cases with varying criteria for the diagnosis of coronary artery disease, 1,721 cases had a true-positive earlobe crease, 1,034
had a false positive, 1,112 had a false negative, and 2,547 had a true negative. In Elliott’s 1,000 consecutive personal cases, including 843 general medical admissions and 157 patients from a cardiac catheterization lab, there were 275 true positives, 98 false positives, 101 false negatives, and 526 true negatives (Elliott, 1983).
had a false positive, 1,112 had a false negative, and 2,547 had a true negative. In Elliott’s 1,000 consecutive personal cases, including 843 general medical admissions and 157 patients from a cardiac catheterization lab, there were 275 true positives, 98 false positives, 101 false negatives, and 526 true negatives (Elliott, 1983).
Exercise for the Student. Construct 2 × 2 contingency tables and calculate the sensitivities, specificities, and positive predictive values for the literature review and for Elliott’s series. What are the predictive values of a negative test? (The answer is in Appendix 11.1.)
Age is a confounding variable. The degeneration of the elastic substance around arterioles, which is thought to be the cause of the crease, is an accompaniment to arteriolar sclerosis and also occurs with aging. However, the association with coronary artery disease exists in all age groups (Elliott, 1983).
A smaller subsequent study failed to find a significant association between earlobe creases and coronary artery disease (Brady et al., 1987). In analyzing such papers, students should ask the following questions: (a) What is the power of the study? Were sufficient patients included to have a reasonable chance of finding an association, if it exists? (b) Were confounding variables, such as hypertension, age, and smoking, handled appropriately (as by a multivariate analysis)? (c) Was there a selection bias? If the risk factor is associated with a disease at a young age, a noncohort study of an elderly population may be negative because of premature “die-out” of affected individuals (this may also account for negative results in some of the later studies of type A personalities), and (d) Is there publication bias? (That is, doctors who believe in modifying risk factors might not be interested in findings that do not suggest a compensable intervention.)
A 10-year follow-up of 264 consecutive patients from a university-based coronary care unit and cardiac catheterization laboratory showed that the number of creased ears was significantly associated with a higher rate of cardiac events. The 10-year cardiac-event-free survival was 43.5% ± 5.7%, 33.0% ± 6.7%, or 17.5% ± 4.6%, p = 0.0003, respectively, for zero, one, or two earlobe creases (Elliott and Powell, 1996). These authors noted that earlobe creases were a more important predictor of future cardiac events than diabetes, hypertension, cigarette use, hypercholesterolemia, family history of coronary disease, or obesity.
Skin Lesions
The external ear may be affected by skin lesions, including solar keratoses and carcinomas, both basal cell and squamous cell. The skin of the pinna and external canal is frequently involved in seborrheic dermatitis and other dermatoses, which cause scaling, edema, and inflammation. A vesicular rash on the pinna occurs in Ramsay Hunt syndrome, caused by a herpes zoster infection of the facial nerve; it should be specifically sought in patients presenting with a facial paralysis (see Chapter 26).
Other Findings
Collections of urate in the form of tophi may be seen in the external ear, but these are quite rare these days owing to the combination of automated uric acid analyses and effective hypouricemic drugs. Nevertheless, if found in an arthritic patient, they could be a valuable clue to a gouty etiology.
See Chapter 17 for the winking earlobe signs.
Protrusion or proptosis of the auricle is reported in 42% of patients with acute mastoiditis, an abnormal-appearing (such as a sagging or narrowed) external auditory canal in 80%, and otorrhea in 26%. The reason for the first two findings is cortical dehiscence of the bone. A history of antecedent otitis media is present in only 45% of patients, although most (88%) have an abnormal- appearing tympanic membrane. Postauricular tenderness and edema (see Chapter 9) are frequently seen. Although the incidence of mastoiditis declined dramatically with the introduction of antibiotics, it still occurs and can cause serious complications. Pain is the presenting symptom in almost all cases (Gliklich et al., 1996).
Palpation
Feel the external ear and tug on it. Is it painful? Pain when pressing the pinna between the thumb and index finger can be found in early cases of chondritis, even before swelling develops. If the pinna itself is not tender but movement causes great pain, the patient will almost always have otitis externa. This will usually be accompanied by swelling of the skin of the external auditory canal, but this finding may be absent in early stages. Otitis media by itself does not produce tenderness with movement of the pinna. Also, check the mastoid process for tenderness (see Chapter 9).
Floppy ears may be seen in relapsing polychondritis. However, not all patients with this disease actually have floppy ears; sometimes the ears simply show inflammation of the pinna. In one series collected in a single institution, 85% of 112 patients with relapsing polychondritis had some evidence of such auricular chondritis at some point during their illness (Michet et al., 1986).
A Note to Sophomores. You have probably not heard of the disease relapsing polychondritis. Thus, it is a “border phrase”: a phrase on the border of this work and another, a textbook of medicine. This is a good time to apply the technique suggested in Chapter 6 for increasing your apparent IQ. Jot down this unfamiliar term and look it up before you go to sleep tonight.
Dr Mendeloff of Maryland, who has seen many patients with Addison disease, notes that stiffening of the earlobe is a useful sign favoring that diagnosis. This phenomenon is distinct from the addisonian calcification of cartilage, which is nondiagnostic, having also been reported in other endocrine disorders such as hyperthyroidism, pseudopseudohypoparathyroidism, diabetes mellitus, acromegaly, and hypopituitarism and in metabolic disturbances including ochronosis and hypercalcemia. In the two cases of acromegaly that had such calcification, pituitary and adrenal insufficiency were not excluded. It has also been seen in sarcoid, presumably because of hypercalcemia. Furthermore, it may occur in conditions that produce localized injury to tissue, such as frostbite, trauma, and inflammation (bacterial chondritis, nonbacterial chondritis, and perichondritis). Miscellaneous etiologies are senile keratosis and idiopathic calcification in the aged (Randall and Spong, 1963).
Internal Inspection
A Method
From your collection of specula, select one that is the correct size for the patient. Use the largest one possible that gives the best view and that provides the least chance of hurting the patient. Disposable specula are preferable. If these are not available, check that the speculum was cleaned (by washing in hot soapy water and rinsing with alcohol) since its last use.
Turn the light on. For examining the patient’s right ear, place the otoscope in your right hand so that your left hand is free to lift the patient’s external ear superiorly, posteriorly, and away from the head to straighten the ear canal of adults and older children. (In infants, you will need to pull inferiorly on the auricle.)
For the left ear, some physicians hold the otoscope in their left hand so that they can manipulate the ear with their right hand without having to cross hands. Others hold the otoscope in their dominant hand for both ears.
Hold the otoscope so that you are comfortable. Most people grasp it like a hammer. Others cradle the battery compartment in the “V” between the thumb and forefinger with the handle pointing up. The latter has the advantage that for an uncooperative patient or excitable child, you can rest the ulnar edge of your hand against the patient’s head so that you will automatically move the otoscope if the patient moves his head and so avoid injuring the ear canal. Examining such a patient in the lateral decubitus position will also reduce the potential movement of the head.
Look through the otoscope. Insert the speculum in the canal, as you tug on the ear with your other hand (see step 2 above). (If you are performing this examination correctly, it should be nearly painless, unless the patient has a furuncle or foreign body in his ear canal.)
If there is cerumen in the canal, clean it out with warm mineral or olive oil and a cotton-tipped swab. Do not use a swab to remove hardened wax as you may impact it against the eardrum.
You may be able to lavage wax from the canal with water and an ear syringe (after softening it with over-the-counter drops such as Debrox or baby oil). Do not lavage the canal if a perforated eardrum is suspected. In any case, be sure to use water of approximately body temperature; cold or hot fluids will set up thermal currents in the endolymph, induce nystagmus, and induce vomiting in some patients (see “Caloric Testing,” Chapter 26).
If you use a blunt cerumen spoon to remove wax, do it only under direct vision, preferably using a head mirror (a skill accrued only with considerable practice, usually from working in the ear, nose, and throat [ENT] clinic). It is also possible to remove the lens from most otoscopes so that you can place the cerumen spoon through the speculum. This author finds it easiest to have an assistant pull on the patient’s ear to straighten the canal while she illuminates the canal with the otoscope held in her left hand, near but not in the canal, and removes the cerumen with an instrument held in her right hand.
If you have access to a suction apparatus and no. 8 and 12 suction tubes, along with a no. 14 ear suction tube, vacuum removal of cerumen is the least traumatic technique. One touches only the cerumen with the suction tube and not the skin of the external canal or the tympanic membrane. Dr Vernon L. Goltry of Boise, Idaho, reports that in more than 30 years of experience, patients have uniformly approved of this technique over all others. It is important, especially with children, to reassure them not to be startled by the sound of the suction.
In truth, many physicians simply do not clean out the canal if it is occluded with cerumen. Sometimes one can get a partial look at the eardrum. If the Weber and Rinne tests (vide infra) are normal and the patient has no complaints referable to the ear, examination of the eardrum is less critical. Otherwise, you must visualize the eardrum.
Reminder: Do not forget to clean (or discard) the speculum on your otoscope before putting it away.
Ear Canal
Inspect the external canal for foreign bodies, such as errant insects, pebbles, sponges, or pieces of food (in the toddler age group). Blood in the external canal can be a useful sign of temporal bone fracture in cases of acute head injury but is more often due to self-inflicted trauma or furuncle rupture. It may also be seen in myringitis bullosa when surface vesicle rupture occurs with sudden disappearance of severe pain.
An exquisitely tender red spot is a furuncle, even if it does not have a white center.
In external otitis, the canal may be edematous, inflamed, and coated with an exudate. It may be difficult to distinguish infectious from noninfectious etiologies. “Swimmer’s ear” due to a variety of bacteria, but especially Pseudomonas, is a common external otitis. It is often accompanied by severe pain and tenderness over the tragus, especially on moving the pinna. Tender regional adenopathy may be present. In fungal infections, tiny fungus particles may be seen in the canal with thick exudate. Fungal parts may be white, gray, black, tan, yellow, or blue-green in color.
External otitis in elderly diabetics is of very serious concern as it may progress to malignant external otitis and osteomyelitis of the temporal bone.
A bony exostosis in the canal is a rounded nodule of hypertrophic bone, frequently seen in persons who swim in cold water. It is nontender and hard. Unless it completely occludes the canal, it is an interesting but harmless finding.
It is to be distinguished from an osteoma, a benign tumor that is attached to the inner third of the canal wall by a bony pedicle.
Tympanic Membrane
Look for the landmarks on the tympanic membrane. Figure 11-3 is a highly schematic diagram. The shadows are seldom seen; it is quite rare to see all three of them in the same patient. Similarly, the flaccid part is usually not so well visualized as the diagram suggests.
Manubrium is the Latin word for handle. The umbo was the protuberance in the middle of a Roman shield; the umbo of the malleus (hammer) is a similar protuberance. Annulus means rim or ring. If the tympanic membrane is retracted, as with blockages of the eustachian tube, the umbo will stand out greatly. If the membrane is bulging outward and inflamed and the landmarks are obscured, the diagnosis of acute suppurative otitis media can be made. If bubbles are seen behind the eardrum, one may diagnose acute serous otitis media. There may also be a fluid level behind the drum. If the fluid is high enough to reach the manubrium of the malleus, this line, which is actually a meniscus, may break in two and appear as two slightly curved lines (menisci) bowed out from the manubrium. Sometimes both the meniscus and the bubbles may be seen.
Blisters, looking like bubbles on the near surface of the drum, are bullae or vesicles. Myringitis bullosa is not diagnostic of mycoplasma infection as it is also seen with bacterial infections or even viral infections as in the Ramsay Hunt syndrome.
Blood behind the tympanic membrane (or hemotympanum) is seen in fractures of the skull. The sign was discovered by the British surgeon W.H. Battle (1855-1936), who also described several other signs of similar significance (see Chapter 9).
Cholesteatomas
The annulus must be carefully inspected over its entire circumference because perforations involving the annulus can lead to cholesteatomas. A cholesteatoma, which may originate from the flaccid part (in primary acquired cholesteatoma) or the tensa part (in secondary acquired cholesteatoma) of the tympanic membrane, is a cystic structure lined with squamous epithelium. Congenital cholesteatomas can develop behind an intact eardrum. Contrary to its name (a misnomer), a cholesteatoma does not contain fat.
A cholesteatoma seems to take on a life of its own, penetrating through the tympanic membrane and sometimes even eroding bone in the mastoid or middle ear through the effects of pressure and enzymatic activity. This effect is best demonstrated by a computerized tomography scan.
A cholesteatoma may appear as a little pearly or fatty fleck, as if a bit of Brie had stuck to the annulus. It might be seen as a silvery ovoid behind an intact eardrum (V.L. Goltry, personal communication, 1998). The only finding on physical examination might be an ear canal filled with mucopus and granulation tissue.
The presence of a cholesteatoma should be suspected when mastoiditis occurs in an older child (Harley et al., 1997). Check for cholesteatoma in patients with facial nerve paralysis; in the preantibiotic era, 2.3% of patients with chronic otitis media had this complication. Cholesteatoma is the main cause of most of the complications of chronic otitis media, which include labyrinthitis, hearing loss, meningitis, extradural or brain abscess, and lateral sinus thrombophlebitis (Nissen and Bui, 1996).