Otalgia overview

# Overview
Otalgia  is one of the leading complaints among children either in the primary care or in emergency setting.
Acute Otitis media, Otitis externa, Otitis media with effusion are the three most common causes responsible for Otalgia in children. 
Otalgia is not always associated with ear disease. It may be caused by several other conditions, such as Impacted tooth, Sinus disease, Inflamed tonsils and infections in the nose and pharynx. The most common causes of ear pain can be identified through the description of the character, onset, and location (coupled with a physical examination).

# Classification
There are two distinct types of otalgia: Primary Otalgia - pain that originates from pathologies within the ear, Referred Otalgia - pain that originates from pathologies outside the ear and is referred to it.

# Pathophysiology
Otalgia or ear pain is one of the most common complaints in the pediatric age group presenting to the primary care or emergency room. Otalgia can be primary or referred. Primary being caused by diseases of the ear and referred being caused by diseases elsewhere. The ear canal is heavily innervated, and the skin lining the canal lies directly against the bone without an intervening subcutaneous layer; therefore, even mild pressure, swelling, or inflammation in this area can cause immediate and severe pain.

# Causes
Otalgia can be caused by diseases involving the ear (e.g otitis media, otitis externa) or can be caused by diseases that cause referred pain to the ear (e.g dental caries, pharyngitis).

# Epidemiology and Demographics
Otalgia is often due to otitis media which is predominantly an infectious disease of children. Otitis externa is less frequent and is often observed in swimmers.

# Risk Factors
An immature immune system, developmental alterations of the eustachian tube, and frequent infections are the major risk factors in children. In adults, smoking, alcohol and immunosuppression form the major contributors among risk factors.

# Natural History, Complications and Prognosis
Natural history, prognosis and complications depend on the disease per se. Acute otitis media, Otitis externa, mastoiditis, cholesteatoma have good prognosis as long as deeper structures of the neck are not involved. If the disease processes persist for more than 6 weeks they have a high chance of getting converted to chronic forms.

# Diagnosis

## History and Symptoms
It is normally possible to establish the cause of ear pain based on the history. It is important to exclude cancer where appropriate, particularly with unilateral otalgia in an adult who uses tobacco or alcohol. 

## Physical Examination
Otalgia is one of the leading complaints in the pediatric age group. Otitis media, otitis externa, and ear trauma are among the leading causes of ear pain. When the ear is the source of the pain (primary otalgia), the ear examination is usually abnormal. When the ear is not the source of the pain (secondary otalgia), the ear examination is typically normal.

## Laboratory Findings
It is normally possible to establish the cause of ear pain based on the history. It is important to exclude cancer where appropriate, particularly with unilateral otalgia in an adult who uses tobacco or alcohol. Common lab tests include complete blood count, differential count of WBC, culture and screening of otorrhea, thyroid function studies - for thyroiditis, erythrocyte sedimentation rate- for temporal arteritis, throat swabs for tonsillitis and pharyngitis.

## CT
Otalgia is ear pain that can be caused by pathology in the ear itself, or pathology in a distant source which causes referred pain to the ear.  A computed tomography (CT) scan is helpful in determining the underlying cause of ear pain.  CT with contrast is indicated when the goal is to determine the extent of the disease. It  is also used in evaluating temporal bone trauma.

## MRI
An MRI is indicated in the evaluation of otalgia if there is any clinical or audiometric suspicion.

## Other Imaging Findings
Other imaging studies in the evaluation of otalgia includes radiography, Panorex imaging, and PET scans.

## Other Diagnostic Studies
Other diagnostic tests include tympanometry, audiometry, and upper aerodigestive tract endoscopy.

# Treatment

## Medical Therapy
Treatment of otalgia lies in identifying the pathology, whether it exists within the ear or elsewhere. Antibiotics are used to treat infectious causes like otitis media, otitis externa, tonsillitis, and pharyngitis. Antivirals can be used for viral causes such as herpes zoster oticus, and antifungals can be used for oral thrush. NSAIDs are used if myalgias and neuralgias are suspected. The patient should be re-examined after a 2 week trial on the  NSAIDs. Appropriate consultation with a neurologist, dentist, gastroenterologist etc., should be done.

## Surgery
Surgery forms the main stay of treatment for major ear pathologies like otitis media (OM), otitis externa, cholesteatoma, mastoiditis, etc., and some non-ear pathologies like TMJ disorders and retropharyngeal abscesses.