The Ear

Published on 02/03/2015 by admin

Filed under Internal Medicine

Last modified 02/03/2015

Print this page

rate 1 star rate 2 star rate 3 star rate 4 star rate 5 star
Your rating: none, Average: 0 (0 votes)

This article have been viewed 1932 times

Chapter 5 The Ear

Salvatore Mangione, MD

“People need to have things trumpeted into their ears several times and from all directions—the first sound pricks up the ear, the second shakes it, and with the third it goes in.”

René Théophile Hyacinthe Laennec, 1821; letter to his cousin Menadec

“The ears should be kept perfectly clean; but it must never be done in company. It should never be done with a pin, and still less with the fingers but always with an ear-picker.”

St. John Baptiste de la Salle (1651–1719), The Rules of Christian Manners and Civility, I

Generalities

The ear is an important site for physical examination; abnormalities may reflect either local or systemic disease. It also is an important sensory organ, whose function can be assessed (albeit in a rudimentary manner) with basic bedside tools.

1 What are the components of the ear?

image External ear (comprising the auricle and the external auditory canal)

image Middle ear

image Inner ear

image Nervous supply

A. External Ear

2 What is the external auditory canal?

It is a 1-cm–long conduit, opening outside through the auricle and delimited inside by the eardrum. It is made by bone in its inner two thirds and cartilage in its outer third. The latter is also rich in sebaceous glands, ceruminous glands (responsible for the production of wax, or “cerumen”), and hair follicles.

3 What is “wax” made of?

Of a combination of desquamated keratin, debris, and secretions by ceruminous glands (which, in turn, are responsible for the wax color). Usually soft and brownish, wax can also become abundant and inspissated.

4 What is the best way to remove cerumen?

There are various schools of thought. The first relies on a number of proprietary substances, all purportedly able to soften the wax when instilled as a solution into the external canal. Another method relies instead on removing the cerumen mechanically, bit by bit through a metal loop. Its effectiveness depends in great part on the examiner. Our favorite method is to flush the canal with warm tap water using a syringe with a 14- to 16-gauge plastic IV catheter. Remember that wax removal is not easy, and serious complications (even hematomas) may result from inexperienced insertion of various wax-removing probes, especially the infamous cotton-tipped swabs—particularly if carried out by patients or their associates.

5 What is the nervous supply of the external canal?

Mostly trigeminal—hence, exquisitely sensitive. Still, the innermost part of the canal is supplied by the vagus (and its stimulation may indeed cause a vagal response, often just a dry cough).

6 What is the auricle (or pinna)?

It is the part of the external ear that is outside the canal (Fig. 5-1). Made of cartilage and skin, it is highly flexible.

image

Figure 5-1 Anatomy of the external auditory meatus.

(From Granger N: Crash Course Anatomy. St. Louis, Mosby, 2007.)

7 What are auricular bumps? What causes them?

Auricular papules or nodules are common. Most are benign, but some represent early neoplasms or clues to underlying systemic disorders. Specific etiologies include:

image Darwin’s tubercle (Fig. 5-2): Benign and congenital nodule near the auricular apex (on the helix, at the junction of upper and middle thirds). Nontender and rarely bilateral, it was first described by the British sculptor Thomas Woolner, a founding member of the Pre-Raphaelite Brotherhood and a spare-time anatomist. Woolner depicted it in his statue of “Puck,” and Charles Darwin was so impressed that he named it the Woolnerian tip. It is an atavistic feature (i.e., a trait typical of our mammalian ancestors—more specifically, monkeys).

image Keloids (Fig. 5-3): Smooth and flesh-colored papule(s) on one or both sides of the earlobe. They indicate an exuberant and fibrotic response to injury.

image Tophi: One or more nontender nodules on the auricular edges. They are named after the Latin tufa (a calcareous and volcanic deposit) and may indeed be mildly hard. They can occur on both helix and antihelix, and usually indicate hyperuricemia and gout.

image Chondrodermatitis nodularis chronica helicis (CNH): This is a common, benign, and painful condition of the most prominent projection of the ear, usually the apex of the helix, but it also may affect the antihelix. It is typical of the right ear of middle-aged to older men, usually fair-skinned individuals with cutaneous sun-damage. In 10–35% of cases, it may also affect women. It is rather common (in a series, the most frequent external ear condition seen in an ear-nose-throat clinic) and is probably due to prolonged and excessive pressure, leading to inflammation, edema, and ischemic necrosis. This eventually degenerates into secondary perichondritis due to the vascular characteristics of the ear. Onset may be precipitated by pressure, trauma, or cold. Sleeping on the affected side is also common. The nodule appears spontaneously and painfully, rapidly enlarging to a maximum size of 4–8   mm, after which it remains stable. It is firm, tender, skin-colored, sharply demarcated, and round to oval in shape. The edge is usually raised, with a central ulcer or crust. It is not associated with systemic disorders.

image

Figure 5-2 Darwin’s tubercle (left) and tophi (right).

(From Seidel HM, Ball JW, Daims JE, Benedict GW: Mosby’s Guide to Physical Examination, 3rd ed. St. Louis, Mosby, 1995.)

image

Figure 5-3 Keloids of the earlobe.

(From Fitzpatrick JE, Aeling H: Dermatology Secrets. Philadelphia, Hanley & Belfus, 1996.)

8 Can I really diagnose gout by looking at the ear?

Yes. Presence of tophi should prompt questions about podagra, chiragra, or gonagra—medieval monikers for monoarticular arthritis of the great toe, hand, or knee, a frequent nuisance of the well-fed (and drunk) aristocracy of old. Similar nodules over extensor surfaces of elbows, hands, or feet are also consistent with tophaceous gout. Since urate crystals precipitate more easily in colder areas of the skin, auricles and nasal cartilages are often the first tophi sites.

9 What are the causes of itching of the ear?

Usually local disorders, often infectious (hence, use otoscopy). Still, systemic disorders may present this way too—for example, diabetes, hepatitis, or lymphoma.

10 What is otorrhea?

It is diarrhea of the ear. In other words, the ear “runs” (which is indeed the meaning of reo in Greek). A discharge from the ear always argues for infection, either in the middle (see later) or external ear. These infections are often associated with pruritus and pain (otalgia).

11 How can the color of the discharge provide clues to its origin?

image A bloody discharge suggests trauma or cancer.

image A clear and serous discharge suggests leakage of cerebrospinal fluid—often posttraumatic.

image A purulent discharge suggests either infection of the middle ear with perforation of the drum (otitis interna) or infection of the external ear (otitis externa).

12 Why is otitis externa “maligna” so malignant?

Because it occurs only in patients with impaired neutrophil function from either quantitative or qualitative disorders (such as leukemia, poorly controlled diabetes, or treatment with corticosteroids and chemotherapy). This leads to a Pseudomonas aeruginosa infection that usually spreads directly into adjacent structures (causing a diffusely swollen and exquisitely tender auricle) and eventually spills into the bloodstream. If missed, it can cause gram-negative sepsis, shock, and even death. Hence, prognosis is guarded, and diagnosis/treatment imperative.

13 What is instead garden variety “otitis externa”?

Simple otitis externa per se is a rather common inflammation of the external canal, seen in subjects who suffer from eczema, psoriasis, or dermatitis, but also individuals with narrow ear canals. The skin can become so swollen as to close the ear canal and thus cause temporary deafness. It also can be so painful as to impede sleep. Discharge from the ear is usually scanty. Once again, the main symptom is otalgia—typically exacerbated by manipulation of the tragus.

14 What is swimmer’s ear?

An otitis externa of swimmers, wherein removal of wax and maceration by water cause a common (but not serious) nuisance.

15 How do you tell an earache due to otitis media from one due to otitis externa?

By pulling up and down the auricle (or tragus). In otitis media, this is painless, whereas in otitis externa, it is painful.

16 What is the value of pushing over the mastoid process?

Tenderness suggests suppurative mastoiditis—an ominous complication of ear infections.

17 Is otalgia always due to ear problems?

No. Ear pain can be referred from other sites too—for example, the teeth, pharynx, and spine. In fact, any process affecting the territory of distribution of trigeminal, facial, glossopharyngeal, vagus, and even C2 and C3 cervical nerves can cause ipsilateral otalgia.

18 Distinguish among vesicles, bullae, and pustules

Vesicles are blisters that contain clear fluid; bullae are blisters larger than 0.5   cm in diameter, and pustules are blisters that contain purulent fluid.

19 What may induce vesicles in the auricle?

Not too many causes: (1) severe contact dermatitis (such as poison ivy); (2) varicella/zoster; and (3) Ramsay Hunt syndrome (painful and vesicular rash of the inferior portion of the auricle, due to herpetic infection of the geniculate ganglion and treated with acyclovir. See questions 48 and 49).

20 What are the causes of auricular red spots?

image Trauma: This also may result in auricular ecchymoses and even hematomas (see question 22).

image Port wine stain: Usually congenital and of only cosmetic importance. One of the most famous port wine stains in history was on the forehead of Soviet President Michail Gorbachev.

image Sturge-Weber disease: Port wine nevus on the upper part of the scalp, associated with intracranial vascular abnormalities that may cause cerebellar calcifications and seizures.

21 Who were Sturge and Weber?

William A. Sturge (1850–1919) was a native of Bristol, England. A devout Quaker, a passionate liberal, and a strong supporter of women’s rights (including free access to medical education), he married a physician named Emily Bovell, with whom he shared a practice in London. An excellent speaker, teacher, and compassionate physician, Dr. Sturge contracted rheumatic fever at age 44, eventually abandoning medicine and moving to the French Riviera. Still, he found the energy to look after Queen Victoria during her four visits to France. After his second marriage to a young archeologist, he studied early Greek art and became the founder and first president of the East Anglia Society of Prehistoric Archaeology, collecting more than 100,000 archeologic pieces, which upon his death were donated to various museums. Throughout his life, he wrote only four medical papers.

Frederick Parkes Weber (1863–1962) is the English physician associated with Rendu-Osler-Weber disease. In addition to these two conditions, he also described Weber-Klippel syndrome and Weber-Christian disease. An enthusiast of physical exercise and an avid climber (like his father), he lived well into his 90s, spending the last part of his life collecting ancient coins and vases, which he eventually donated to the British Museum.

22 What is a tender and swollen auricle?

It is an uncommon but dramatic event. A diffusely swollen auricle is usually due to:

image Trauma: Easily identifiably by a history of recent altercation, especially if supported by other evidence of trauma, like a broken nose or a black eye. In fact, a “cauliflower” ear auricle is a time-honored occupational hazard of boxers, first portrayed in a beautiful Hellenistic statue of a resting fighter (Fig. 5-4

Buy Membership for Internal Medicine Category to continue reading. Learn more here

Related posts:

The Eye The Bedside Diagnosis of Coma Chest Inspection, Palpation, and Percussion The Musculoskeletal System Heart Murmurs The Cardiovascular System