OTALGIA CAUSES &MANAGEMENT

By dr humra shamim

introduction Otalgia is defined as ear pain. Two

separate and distinct types of otalgia exist. Pain that originates within the ear is primary otalgia; pain that originates outside the ear is referred otalgia

Typical sources of primary otalgia are external otitis, otitis media, mastoiditis, andauricular infections. Most physicians are well trained in the diagnosis of these conditions. When an ear is draining and accompanied by tympanic membrane perforation, simply looking in the ear and noting the pathology can make the diagnosis. When the tympanic membrane appears normal, however, the diagnosis becomes more difficult.

Neurophysiology of pain Pain may be nociceptive or neuropathic. Peripheral nocireceptors respond to

noxious stimuli such as phycical trauma,thermal or chemical injury or inflammation.

Neuropathic pain results from core damage to the peripheral or cns systems or from an abnormality in pain processing system

Most otalgia is mediated by via unmyelinated pain fibres which characteristically cause a dull ache .

Neuroanatomy The common sensory supply of the ear

reflects a watershed between brachial and postbranchial innervation between cranial and cervicospinal nerves.

There is both overlap of relative contribution from sensory afferent nerves and individual variatins in distributions

Pathophysiology The sensory innervation

of the ear is served by the auriculotemporal branch of the fifth cranial nerve (CN V), the first and second cervical nerves, the Jacobson branch of the glossopharyngeal nerve, the Arnold branch of the vagus nerve, and the Ramsey Hunt branch of the facial nerve.

Neuroanatomically, the sensation of otalgia is thought to center in the spinal tract nucleus of CN V. Not surprisingly, fibers from CNs V, VII, IXand X and cervical nerves 1, 2, and 3 have been found to enter this spinal tract nucleus caudally near the medulla. Hence, noxious stimulation of any branch of the aforementioned nerves may be interpreted as otalgia.

Reports document that not all otalgia originates from the ear. Many remote anatomic sites share dual innervation with the ear, and noxious stimuli to these areas may be perceived as otogenic pain. By definition, referred otalgia is the sensation of ear pain originating from a source outside the ear.

To better understand referred otalgia, the physician first must understand the anatomic distribution of nerves associated with the ear. Irritation of these nerves, as well as irritation of distant branches of these nerves, can cause the perception of pain within the ear.

A central common pathway for otalgia ,whether primary or reffered , is probabaly the spinal tract of the trigeminal nerve

Fibres from cranial nerve V,VII,IX,X and cervical nerves c1,c2 converge here and all play some role in sensory supply of the ear and temporal bone.

The auriculotemporal branch of V nerve innervates the anterosuperior external canal and pinna along with temporomandibular joint

Cranial nerve IX innervates the posterior external canal ,meatus and tympanic membrane,but also the ipsilateral oropharynx

Tympanic branch of IX nerve (jacobson’s nerve forms the tympanic plexus ,innervating middle ear cleft.

The auricular branch of vagus (arnold’s nerve)has a similar otologic ,but cranial nerve X has a vast dispersion to the viscera of neck and even mediastinum.

The upper cervical nerves c2 ,c3 via the great auricular nerves and lesser occipital nerve supply the cranial surface of the pinna ,but also the skin and muscles of the neck and cervical spine

This rich innervation of the ear allows central misinterpretation of the origin of pain arising from throughout the head and neck and is the basis for referred otalgia

Otalgia causes Otologic causes External ear Middle ear inner ear

Non otologic causes

Reffered pain Tmj Throat Teeth Nose &

nasopharynx Neuralgia tumors

Etiology of Primary Otalgia Pinna Laceration & bite Hematoma Otitis externa Perichondritis Infected pre-auricular

sinus Frostbite, sunburn Neoplasm

External auditory canal Impacted wax Foreign body Keratosis obturans Otitis externa Herpes zoster oticus Exostoses Neoplasm

External ear External auditory

canal Block ear Hearing loss Pain with impaction Associated infection Treatment by removal syringing suction curettage

Foreign body in the ear

External ear

External ear Otitis externa -severe pain -tenderness -postaural swelling -Sweling in canal -discharge

External ear Otomycosis-produces Intense itching, Discomfort pain

External ear Malignant otitis externa Pseudomonas aeroginosa Diabetes mellitus Infiltrating infection Invades bone Affects cranial nerves V,VII,IX,X Sometimes life threatening Treatment: high dose antibiotics, surgery to debride dead bone hyperbaric oxygen.

External ear Ramsay hunt syndrome Herpes zoster of VII nerve Varicelliform rash over pinna Severe otalgia Facial palsy Bullous myringitis Large vesicles on drum & canal Extreme otalgia Sensorineural deafness Probably a viral neuropathy of VIII nerve

Middle ear causes Bullous myringitis Acute otitis media secretory otitis media Traumatic perforation Hemotympanum Otitic barotrauma Neoplasm

Middle ear Acute otitis media Bacterial or viral infection of middle ear Usually accompanying a URTI OTOSCOPY:bulging ,congested TM,loss of

land marks,impaired mobility,acute otalgia

Chronic otitis media

Middle ear

Middle ear Complications of otitis media Mastoiditis Petrositisis Labyrinthitis Facial paralysis Bezold’s abscess Intracranial spread -meningitis -brain abscess -subdural empyema -lateral sinus thrombosis

Middle ear Otitis media with effusion• Pain ,block/fullness ear• Deafness• Autophony• popping

Middle ear Traumatic perforation of tympanic

membrane• Pain ,block,hearing loss• h/o blast injury or being hit on ear• Often seen in antero-inferior TM• Most heal spontaneously • Do not put eardrops

Inner ear Acoustic trauma Meniere’s disease Vestibular schwannoma

Meniere’s disease Ménière disease is associated with a

sensation of aural fullness, in addition to vertigo,tinnitus, and fluctuating hearing loss.

The perception of aural fullness may be described as ear pain in conditions associated with endolymphatic hydrops

Vestibular schwannoma Otalgia due to VS has been variously attributed to

involvement of the nervus intermedius or dural stretching.The former suggestion is favoured by the mastoid location of pain and by the remarkably high prevalence (95· percent reported) of hypoaesthesia of the posterior wall of the external auditory canal (the basis of Hitselberger's sign) due to involvement of sensory fibres of the facial nerve. Innervation of the possibly stretched dura of the posterior fossa is via the meningeal (recurrent) branch of CN X, although this is questioned, meningeal branches of CN XII, but primarily from the first three cervical nerves ascending through the foramen magnum. The little publicized association of otalgia with VS further reinforces the case for imaging.

Causes of reffered otalgia

A. Via trigeminal nerve Teeth: infection, impacted 3rd molar, malocclusion Oral cavity: infection, ulcer, malignancy, Ludwig’s

angina, sialadenitis, salivary calculus Temporo-mandibular joint: arthritis, dysfunction Nose & PNS: impacted DNS, sinusitis, neoplasm Nasopharynx: infection, post- adenoidectomy,

adenoiditis, tumor Trigeminal neuralgia

B. Via glossopharyngeal nerve Tonsil: tonsillitis, peritonsillar abscess, post-

tonsillectomy, neoplasm Oropharynx: infection, ulcer, retropharyngeal +

parapharyngeal abscess, trauma, neoplasm

Eagle’s syndrome (stylalgia) Glossopharyngeal neuralgia

C. Via facial nerve: Herpes zoster oticus, vestibular schwannoma

D. Via vagus nerve: Larynx + hypopharynx: neoplasm, infection, tuberculosis, trauma, foreign body

E. Via second & third cervical nerves: Herpes zoster, cervical spondylosis & arthritis

Non otologic causes Neuralgias• Trigeminal N• Glossopharyngeal N• Sphenopalatine N

Non otologic causes Other• TMJ disorder• Dental conditions• stylalgia• Cervical spine disorders

Dental causes Dental disorders are the most common cause

of referred pain to the ear. Of this group of disorders, temporomandibular dysfunctions account for most patients.[1]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. Other odontogenic causes range from abscessed teeth to poorly fitting dentures.

Oral cavity Within the oral cavity, the sensory

innervation becomes quite complex. The tongue receives fibers from the glossopharyngeal nerve, the facial nerve receives fibers from the chorda tympani, and the trigeminal nerve receives fibers from the lingual branch and vagus nerve posteriorly. All these nerves have distributions in the ear as well

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.

Eustachian tube dysfunction causing an intermittent inability to equalize middle ear pressures may manifest with such minimal tympanic membrane bulging or retraction that even otomicroscopy does not detect an abnormality. The problem may be as simple as a sensitive ear canal that requires protection from cold winds along with reassurance that nothing is actually wrong.

Neck problems can also refer pain to the ears. These disorders include cervical osteoarthritis, cervical myofascial pain syndrome, and traumatic injuries.[2, 3] The cervical spine is sensitive and well supplied by the cervical nerve roots. Muscular pain from the trapezius or sternocleidomastoid may project postauricularly to the mastoid and occipital area.

Sensory branches of the vagus and glossopharyngeal nerves supply upper aerodigestive tract mucosal areas such as the nasopharynx, oropharynx, hypopharynx, and larynx. The vagus continues caudally and supplies sensory enervation to the bronchus, esophagus, and heart as well. Irritative lesions at any of these sites may mimic stimulation of Arnold and Jacobson nerves.

Tonsillitis and pharyngitis are very common causes of earaches in children. Less commonly, laryngitis, laryngeal tumors, esophagitis, and even angina pectorismay manifest as otalgia. Eagle syndrome, in which the elongated styloid process irritates branches of CN VIV and CN IX, is even rarer. This crossing of signals works both ways; thus, stimulation of the ear canal may be felt as a tickle in the throat or may produce the cough reflex

How to arrive at a diagnosis? History Features suggestive of primary otalgia

(due to ear disease): • hearing loss; • aural discharge; • vertigo; • unilateral rather than bilateral

symptoms

Onset-Sudden : furunclosis ,acute otitis media ,otitic barotrauma-Gradual :otitis externa secondary to CSOM ,malignancy, malignant

otitis externaDuration -Short duration:asom ,perichondritis of eat pinna-Long duration:malignancyNature of pain-Dull:exematous otitis externa,secretory otitis media,impacted wax-Sharp:furunculosis ,otitic barotrauma -Throbbing pain:ASOM

Relieving facors :pain relieved with discharge from the ear-acute suppurative otitis media(ASOM)

Aggravating factors:-Pain increasing on swallowing –ASOM-Pain increasing on yawning and chewing-

furunculosis arising from anterior canal wall.

Symptoms suggesting referred otalgia: pain on chewing/trismus; dysphagia/odynophagia; hoarseness; risk factors (smoking/alcohol history); neck swelling/goitre; cervical musculoskeletal symptoms; dental history/recent treatment

Features of neuropathic pain: radiation, e.g. to throat; typical time course/duration; quality of pain; trigger zone/precipitating factors, e.g

swallowing

Otologic history - Tinnitus, hearing, vertigo Sinuses Pulmonary history Cardiac history Dental history - Mastication GI history - Dysphagia, esophagitis, reflux Neurologic history - Neuralgias Musculoskeletal history - Arthritis Cervicofacial history Myalgias Trauma - Cervical spine (C-spine) Infections - Tonsillitis, pharyngitis

Examinatiom

Primary otalgia: • inspection of ear and otoscopy; • palpation for tenderness; • aural examination with teleotoscope and microscope; • tympanometry. Referred otalgia: • cranial nerve (CN) examination, especially V, VII, IX and X; • palpation of cervical lymphatic chain; • assessment of cervical spine mobility/tenderness; • palpation of TMJ and pterygoid muscles; • exclude trismus; • dental inspection for caries, absent dentition and malocclusion; • direct and fibreoptic examination oropharynx and laryngopharynx; • palpation of oropharynx to seek induration trigger zone or styloid bone

WORKUP Frequently, the workup suggests that otalgia may be a

problem of dental origin. A complete blood cell count may indicate an occult

infection. Thyroid function and erythrocyte sedimentation rate

(ESR) studies may reveal thyroiditis and temporal arteritis. Chest radiography to seek bronchogenic pathology may be necessary.

The perception of aural fullness may be described as ear pain and is observed in conditions associated with endolymphatic hydrops and eustachian tube dysfunction.

Ménière disease can be diagnosed by history, audiometrics, and a battery of laboratory tests.

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 (NSAIDs) may be helpful.

Preliminary testing (appropriate to symptoms) should include the following: Barium swallow ECG C-spine radiography Chest radiography Panorex imaging

IMAGING STUDIES Dental radiography CT scanning: Obtain CT scans of the head or

temporal bone, sinuses, and/or neck when no obvious source of the pain can be found. The scan usually includes a brief survey of the sinuses and intracranial contents. CT scanning can reveal significant information about the temporomandibular joint or can be used to diagnose intratemporal lesions.

MRI: If indicated by clinical or audiometric suspicion, an MRI may be necessary to define a cerebellopontine angle or other intracranial tumor.

Panorex imagery: Panorex imagery is quite useful in diagnosing temporomandibular joint dysfunction, odontogenic pathology, and styloid abnormalities. Referral to a competent dentist or oral surgeon may be indicated.

PET scanning: As this emerging modality for identifying malignant tumors becomes more readily available, it may be possible to diagnose cancer earlier. PET images fused with CT or MRI adds tremendously detailed information about the location of head and neck neoplasms.

If history and physical examination findings are inconclusive, perform other diagnostic procedures if suspicion still exists for the following conditions: Upper respiratory tract tumor - Panendoscopy, chest

radiography, CT scanning, or MRI as needed Sinus disease - Sinus CT scanning Intracranial/intratemporal disease - Audiometric battery and CT

scanning or MRI as needed Autoimmune disease - ESR, thyroid function studies (thyroiditis,

temporal arteritis) Endolymphatic hydrops - ESR, thyroid function test (TFT),

fluorescent treponemal antibody absorption (FTA-Abs) test, fasting glucose, lipid profile

Eustachian tube dysfunction - Autoinsufflation (consider myringotomy)

Psychiatric disorder - Consider psychiatric consultation.

Whilst there is an individual variation in pain threshold and perception, it is often an alarming symptom to the patient. Chronic pain in true ear disease can indeed suggest dural and skull base extension.

A presenting history of 'recurrent ear infection‘ must be questioned and may represent a self diagnosis of cause of recurrent earache, reinforced by inexpert otoscopy in primary care .

Earache, in the absence of discharge,hearing loss,audiovestibular upset or otoscopic abnormality during an attack, should suggest a secondary, referred otalgia.

Expert dental examination may reveal impaction,caries or malocclusion and confirm temporomandibular disorder .

Careful direct and endoscopic evaluation of the uppeaerodigestive tract is vital in unilateral otalgia and should not be neglected even with positive findingsas above. A tender TMJ does not exclude a diagnosisof tonsillar carcinoma.

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