Otalgia

Otalgia

OTALGIA

 

1)What is Otalgia?

 

Otalgia (ear ache) is ear pain. Primary otalgia is ear pain that originates within the ear (pathologic conditions of the ear itself). Referred otalgia is ear pain that originates outside of the ear, conditions in the distributions of cranial nerves V, VII, IX or X, or the cervical plexus in the distribution of C2 and C3. Otalgia is not always associated with ear disease. When primary otalgia is present, an ear examination typically shows abnormality of the outer or middle ear. When referred otalgia is present, the ear examination is typically normal. It may be caused by several conditions like inflamed tonsils, infections in the nose and pharynx, throat cancer. 

 

2) What causes Primary Otalgia?

 

Ear pain can be caused by disease in the external, middle and inner ear, mastoid or tympanic membrane. Common causes of primary otalgia are: infections of outer ear or ear canal and middle ear (otitis media), Eustachian tube dysfunction (inability for the middle ear to pressurize properly), tumors of the temporal bone, and cholesteatoma. In most cases of otalgia in children, it is primary, whereas less than half of the cases of otalgia in adults are primary.

 

Lesions of the external canal:

 

                 Otitis externa

                 Furuncle

                 Cerumen, foreign body (including live insects)

                 Trauma

                 Herpes zoster

                 Pericondritis of pinna

                 Otomycosis

                 Benign or malignant tumors

                 Granuloma

                 Bell’s palsy

                 Cholesteatoma and keratosis of external canal

                 After surgery

         Radiation therapy

         Local manifestations of skin disorders (lupus, psoriasis, leukemia)

         Parotid and soft tissue disorders extending into ear canal

 

Lesions of the middle ear:

 

               Infective otitis media (acute or chronic)

               Otitis media with effusion

               Cholesteatoma        

         Acute mastoiditis     

         Tumors like glomus tympanicum and jugulare

         Surgery like application of ventilation tube, myringoplasty, tympanoplasty

          Barotrauma

          Acute obstruction of Eustachian tube

          Trauma

 

3) What is referred pain?

 

Referred pain is an incompletely understood phenomenon wherein nerve impulses emanating from a distant or deeper structure are localized to a more superficial structure. The site of pain referral generally follows the dermatomal rule. Pain spreads from one area to another through nerve branches that have a common central origin within the same segments of the gray matter of the spinal cord. When pain is referred to the ear from a lesion, it is likely the ear and the area containing the lesion receive sensory innervations from the same cranial nerve and that spread occurs by way of central connections within the gray matter of the brainstem.   

 

4) What causes Referred Otalgia?

 

Due to the complex nature of the nervous system, determining the origin of referred otalgia can be extremely difficult because it can come from many other areas of the body. Lesions in the ear rarely produce pain in more distant areas, but many remote areas refer pain to the ear. When the patient complains of otalgia through having a normal external canal and tympanic membrane, a number of sources of pain should come to mind. In about one-half of cases the cause will be of dental origin either occurring from the teeth themselves or from the temporomandibular joint.

 

Lesions of referred pain:

 

                 Nasopharynx – infection, neoplasm, adenoidectomy

                 Salivary glands – infection, calculi, neoplasm

                 Jaw – malocclusion, temporomandibuler joint artritis

                 Elongated styloid process

                 Petrous aneurysms

                 Oesophagus – foreign body, reflux, neoplasm

                 Oropharynx, tongue, larynx – inflammation, neoplasm

                 Temporalis arteritis

                 Thyroiditis

                 Trigeminal neuralgia (referred pain of Vth cranial nerve)

                 Ramsay Hunt Syndrome (referred pain of VIIth cranial nerve)

                 Tonsillitis (referred pain of IXth cranial nerve)

                 Dental problems (pulpitis, periapical periodontitis, periapical abscess, impacted third molar teeth)

                 Cervical spine arthritis

                 Sinusitis

                

If ear examination is normal in an adult with chronic otalgia, the possible diagnosis is carcinoma of the head and neck region until proven otherwise.   

 

5) How is the nerve supply of the ear structures?

 

Extrinsic causes produce pain in the ear reflex by lesions remote from the ear itself. This is often referred to as reflex or referred otalgia. In order to interpret the significance of referred pain in the ear, it is necessary to know the nerve supply of the ear and to know to what other organs the same or related nerves are distributed.

 

Ear has a sensory innervation provided by four cranial nerves and two spinal segments. Because of this, non-otologic (non-ear) parts of the body innervated by these neural pathways may refer pain to the ear. These pathways are:

 

  • Trigeminal nerve (cranial nerve V)
  • Facial nerve (cranial nerve VII)
  • Glossopharyngeal nerve (cranial nerve IX)
  • Vagus nerve (cranial nerve X)
  • Second and third spinal segments (C2 and C3)

 

Trigeminal nerve: The auriculotemporal branch of the mandibular division (V3) of trigeminal nerve (cranial nerve V) innervates the skin of the tragus and part of the helix, anterior and superior walls of the external auditory canal, anterior portion of tympanic membrane. Therefore otalgia can also be referred via trigeminal nerve (cranial nerve V) from teeth, gums, mouth, jaw and face.

 

Facial nerve: facial nerve (cranial nerve VII) innervates posterior tympanic membrane and part of the posterior wall of the external auditory canal.

 

Glossopharyngeal nerve: Cranial nerve IX innervates the posterior part of external canal and tympanic membrane, mastoid and Eustachian tube. Tympanic branch of cranial nerve IX ascends into the middle ear and forms the tympanic plexus. Tympanic plexus that lies on the promontory is formed mainly by nerves derived from the tympanic branch of the glossopharyngeal nerve but also receives branches from the geniculate ganglion of the facial nerve. Sympathetic branches from the carotid plexus join the tympanic plexus. Cells in the mastoid receive their sensory supply through a mastoid branch of the tympanic plexus Otalgia can be referred via cranial nerve IX from the posterior tongue, tonsils and pharynx.

 

Vagus nerve: Auricular branch (Arnold’s nerve) of the vagus nerve (cranial nerve X) innervates part of cavum conchae, posterior wall of external canal and posterior part of tympanic membrane. Otalgia can be referred via vagus nerve from pharynx, larynx, trachea, diaphragm, thyroid gland, esophagus, and any other thoracic and abdominal structures.

 

Upper cervical nerves (C2 and C3) (great auricular nerve and lesser occipital nerve): Upper cervical nerves particularly posterior branch of great auricular nerve and lesser occipital nerve innervate posterior surface of external ear and some of the cavum conchae. The skin overlying the mastoid is innervated by the mastoid branches of the great auricular and lesser occipital nerves. Otalgia may be referred via cervical plexus from structures in neck and cervical spine.

 

6) How do non-otologic lesions cause otalgia?

 

Referred pain pathways responsible for most cases of otalgia involve the same three cranial nerves that innervate the external auditory canal and middle ear. Painful impulses originating in the region of a diseased lower molar tooth or temporomandibular joint would be traced by way of the gasserian ganglion to the spinal nucleus of trigeminal (cranial V) nerve in the brainstem. This nucleus also connects with ear structures by way of other sensory branches of the third division that innervate the wall of the external canal and tympanum.

 

The skin lining the external ear canal lies directly against the bone without a subcutaneous layer, therefore even mild pressure, swelling or inflammation in this area can cause severe pain.

 

Irritative impulses from the tongue or tonsil travel through the glossopharyngeal (cranial IX) nerve and its ganglia to enter the somatic sensory nucleus of that nerve within the medulla. This nucleus also receives the sensory branches of the ninth cranial nerve from the middle ear and adjacent structures.

 

The somatic afferent pathways of the vagus (cranial X) nerve from the larynx ascend through the peripheral ganglia to the spinal nucleus in the medulla and here connect with afferents from the concha and deeper structures of the ear.

 

Lesions of the anterior two-thirds of the tongue and inflammatory conditions of the parotid gland refer pain along the auricular branch of the auriculotemporal nerve. Referred pain from the submaxillary and lingual salivary glands via the lingual nerve may cause pain in front of the ear. An inflammation on the anterior one-third of the tongue may cause pain in front of the ear, whereas an ulceration of the posterior one-third of the tongue, such as a beginning carcinoma, may cause pain within the ear itself.

 

Patients with acute and chronic infections of the tonsils frequently complain of otalgia. Lesions of the palate, pharynx, nasopharynx, region of the Eustachian tube, produce pain deep in the ear. Otalgia is often the earliest sign of a beginning malignancy in the nasopharynx. The ninth cranial nerve is involved in this referred pain pattern.

 

Sensory branches of the vagus and glossopharyngeal nerves supply upper aerodigestive tract mucosal areas such as the nasopharynx, oropharynx, hypopharynx and larynx.Lesions of the larynx such as malignancy or tuberculosis may cause reflex otalgia, secondary to irritation of the superior laryngeal branch of the vagus nerve. The vagus continues caudally and supplies sensory innervation to the bronchus, esophagus and heart as well. Irritative lesions at any of these sites may mimic stimulation of Arnold and Jacobson nerves. 

 

Acute and chronic forms of thyroiditis may present as throat and ear pain, but tenderness will be maximal over the thyroid lobe on that side.

 

An unsuspected source of otalgia is elongation of styloid process with protrusion into the tonsillar fossa (Eagle’s syndrome). Ear pain combined with throat discomfort should alert the examiner to palpate the tonsillar fossa.

 

Sinusitis is another very common source of ear pain. The neural pathway is along the second branch of the trigeminal nerve and the auriculotemporal nerve. Because the trigeminal nerve supplies the nasal cavity, patients with inflammatory mucosal contact points and nasal obstruction may develop symptoms in their ears. The proximity of the Eustachian tube orifice also contributes to the problem.

 

Neck problems can also refer pain to the ears. These disorders include cervical osteoarthritis, cervical myofascial pain syndrome and traumatic injuries. Muscular pain from the trapezius or sternocleidomastoid may project to the mastoid and occipital area.

 

Sometimes pain may be from irritation of the nerves themselves without an inciting source. These disorders are termed neuralgias. Neuralgias are typified by lancinating pain in the distribution of the involved nerve. Otologic symptoms of trigeminal neuralgia are referred along its auriculotemporal branch. Geniculate neuralgia is rare but can be observed in Ramsay Hunt syndrome. This neuralgia involves the irritation of facial nerve sensory fibers, which corresponds to the pain sensation felt within the auricle. Sphenopalatine and vidian neuralgias cause similar aural pain via crossing fibers of the greater superficial petrosal nerves and the facial nerves. Glossopharyngeal neuralgia, which causes a phantom tonsillar pain, may also cause otalgia by simulating excitation of the Jacobson nerve.

 

Eustachian tube dysfunction causing an intermittent inability to equalize middle ear pressure may manifest with such minimal tympanic membrane bulging or retraction that even otomicroscopy does not detect an abnormality.

 

 

7) What is the differential diagnosis?

 

  • Aberrant carotid artery in middle ear
  • Acute laryngitis
  • Acute otitis media
  • Adenoidectomy
  • Barosinusitis
  • Bell’s palsy
  • Bullous myringitis (viral infection of tympanic membrane)
  • Carotid artery aneurysms
  • Cervical radiculopathy or artritis
  • Cholesteatoma
  • Chronic laryngitis
  • Complications of otitis media
  • Contact granuloma
  • Costen syndrome (temporomandibuler joint pain)
  • Deep neck infections
  • Eagle syndrome (elongated styloid process)
  • Eustachian tube dysfunction
  • External ear (benign and malignant tumors)
  • External ear (infections)
  • External ear (inflammatory disease)
  • External ear (malignant otitis externa: a necrotizing, potentially fatal, pseudomonas infection of skull base affecting immunosuppresses individuals and diabetics)
  • Fractures (mandibular, maxillary, zigomatic)
  • Herpes simplex virus infection of vagus nerve
  • Herpes zoster oticus (Ramsay hunt syndrome)
  • Keratosis obturans (accumation of desquamated keratin in the external canal)
  • Malignant nasopharyngeal tumors
  • Malignant tumors of the base of tongue
  • Malignant tumors of the floor of the mouth
  • Malignant tumors of the nasal cavity
  • Malignant tumors of the paranasal sinuses
  • Malignant tumors of the temporal bone
  • Malignant tumors of the tonsils
  • Mastoiditis
  • Metastatic lesions of the neck
  • Migraine
  • Neuralgia of geniculate ganglion or tympanic branch of cranial nerve IX
  • Neuralgia of intermedius, or vagal nerves
  • Otitis media with effusion
  • Neck cancer, unknown primary site
  • Parapharyngeal space tumors
  • Parotid gland (parotitis, neoplasm)
  • Rheumatoid arthritis or ankylosing spondylitis involving cricoarytenoid joint)
  • Serous otitis media
  • Sinusitis, acute or chronic
  • Skull base infection and tumors
  • Slude neuralgia (sphenopalatine neuralgia)
  • Teeth (dental infection, malocclusion, impacted teeth, bruxism)
  • Temporal bone fractures
  • Thyroid cancer
  • Tonsillectomy
  • Tonsillitis and peritonsillar abscess
  • Trigeminal neuralgia
  • Whiplash injury

 

 

8) What are the clinical manifestations?

 

Otalgia may be described as burning, aching, throbbing, stabbing or like an electric shock. It may be mild or severe, constant or intermittent. Severity of the pain does not necessarily correlate with the severity of underlying pathology. Vesicles on the auricle or in the external auditory canal (Ramsay Hunt syndrome, Herpes zoster oticus), painful bullae on tympanic membrane (bullous myringitis), hearing loss (disorders od middle ear and mastoid) may be seen. Chronic otitis media itself is not painful, but it may be associated with painful complications like petrous apicitis, dural venous sinus thrombosis, temporal lobe and cerebellar abscess, extradural, subdural or brain abscess, meningitis, otitic hydrocephalus.

 

 

9) What is the diagnostic workup?

 

  • Careful examination (inspection and otoscopy) of the auricle, external ear canal and tympanic membrane (any ear pathology), manual pressure on tragus (pain suggests inflammation of the external canal), careful palpation of the external canal with a cotton-tipped applicator (early neoplasm of external canal), tympanometry (Eustachian tube disorder, alterations in middle ear pressure, fluid in middle ear), audiograms (associated hearing loss). Rhinoscopy, nasopharyngoscopy, indirect laryngoscopy, upper aerodigestive tract endoscopy are mandatory.

 

  • If no ear disease is identified, careful history and examination of head and neck necessary. Risk factors (smoking, alcohol use, previous carcinoma), suggestive symptoms (hoarseness, weight loss, dysphagia, odynophagia, progressive nasal obstruction, neck pain, bruxism, toothache, jaw pain, pain with chewing or jaw opening, dyspnea, anorexia, malaise, night sweats, fever) and signs (middle ear effusion, neck mass, epistaxis) are all identified. 

 

  • Examination should include structures innervated by cranial nerves V, VII, IX and X as well as the upper cervical nerves. Dental disorders are the most common cause of referred pain to the ear. Teeth must be examined carefully (obvious caries, malocclusion, missing molars, abscessed teeth, poorly fitting dental prostheses, wear facets on the canins). Temporomandibuler joint must be palpated with the mouth both closed and widely open. Bruxism, degenerative joint disease, or stress can lead to internal derangements within the joint. The third division of the trigeminal nerve and the auriculotemporal nerve mediate pain, which is often perceived deep within the ear.

 

  • CBC may indicate an occult infection. Thyroid function and erythrocyte sedimentation rate (ESR) studies may reveal thyroiditis and temporal arteritis.

 

  • Radiological studies should be considered in selected patients (dental radiography, roentgenography of paranasal sinuses, cervical spine and chest, barium swallowing , endoscopy, direct laryngoscopy, fiberoptic nasopharyngoscopy, CT or MR imaging of skull base and neck, conventional or MR angiography).  CT scans of the head or temporal bone, sinuses, and/or neck may be indicated when no obvious source of the pain can be found. MR may be necessary to define a cerebellopontine angle or other intracranial lesin. Panorex imagery is useful in diagnosing TMJ dysfunction, odontogenic pathology and sytloid abnormalities.

 

  • In suspicion of;

 

Upper respiratory tract tumor: panendoscopy, chest radiography, CT or MR,

Sinus disease: sinus CT

Intracranial-intratemporal disease: audiometric tests, CT or MR

 

  • Biopsy should be performed for all suspicious lesions. 

 

 

10) What is the treatment ?

 

Treatment depends on the underlying pathology.

Use antibiotics in treating various types of infections (tonsillitis, pharyngitis, sinusitis). Use antivirals if the causative agent is suspected to be viral such as in cases associated with herpes zoster. Antifungals are indicated if the source is caused by a fungus (oral thrush, candidiasis). Antiulcer/antacid medications can be used for esophagitis and gastroesophageal reflux.

 

 

In the absence of evident observable pathology, neuralgic otalgia is treated with analgesics and anticonculsants (carbamazepine, gabapentin, phenytoin).

In cases of otalgia  for with trigeminal, intermedius, glossopharyngeal or vagal neuralgia that do not respond to medical treatment, nerve section, neurolysis, or microvascular decompression may be considered. But these procedures have significant failure rate and severe complications. 

Despite the full battery of testing, a group of patients always remains for whom an etiology is not evident. If not contraindicated, a brief course of nonsteroidal anti-inflammatory agents may be helpful.

 

Perform a detailed search for the underlying diagnosis before initiating treatment. Starting analgesics before reaching a diagnosis increases the difficulty of determining the cause and may possibly obscure a life-threatening condition such as an occult cancer.