User:JennDS/sandbox

Primary ear pain[edit]
Ear pain can be caused by disease in the external or middle ear(because of infection), or inner ear, but the three are indistinguishable in terms of the pain experienced.

External ear pain may be: Middle ear pain may be:
 * Mechanical: trauma, foreign bodies such as hairs, insects or cotton buds.
 * Infective (otitis externa): Staphylococcus, Pseudomonas, Candida, herpes zoster, or viral Myringitis. (See Otitis externa)
 * Mechanical: barotrauma (often iatrogenic), Eustachian tube obstruction leading to acute otitis media.
 * Inflammatory / infective: acute otitis media, mastoiditis.

Referred(secondary) pain[edit]
The neuroanatomic basis of referred earaches rests within one of five general neural pathways. The general ear region has a sensory innervation provided by four cranial nerves and two spinal segments. Hence, pathology in other "non-ear" parts of the body innervated by these neural pathways may refer pain to the ear. These general pathways are: Dental disease may cause pain in the region of the ear. E.g. dental caries causing pulpitis and/or periapical periodontitis (which may be associated with a periapical abscess) in a tooth can be referred via the auriculotemporal nerve (a branch of the trigeminal nerve), the tympanic nerve (a branch of the glossopharyngeal nerve) or via the auricular nerve (a branch of the vagus nerve). Temporomandibular joint dysfunction, impacted third molar teeth, and lesions of the floor of mouth or ventral surface of the tongue (underside of the tongue) are other possible causes of dental conditions which can cause ear pain.
 * Via Trigeminal nerve [cranial nerve V]. Rarely, trigeminal neuralgia can cause earaches. Oral cavity carcinoma can also cause referred ear pain via this pathway.
 * Via Facial nerve [cranial nerve VII]. This can come from the teeth, the temporomandibular joint (due to its close relation to the ear canal), or the parotid gland.
 * Via Glossopharyngeal nerve [cranial nerve IX]. This comes from the oropharynx, and can be due to pharyngitis, pharyngeal ulceration, tonsillitis, or to carcinoma of the oropharynx (base of tongue, soft palate, pharyngeal wall, tonsils).
 * Via Vagus nerve [cranial nerve X]. This can arise from the laryngopharynx in carcinoma of this area, or from the esophagus in GERD.
 * Via the second and third spinal segments, C2 and C3.

Causes[edit]
Ear pain has a variety of causes, the majority of which are not Life-threatening. Ear pain can originate from a part of the ear itself, known as primary ear pain, or from an anatomic structure outside the ear that is perceived as pain within the ear, known as secondary ear pain. Secondary ear pain is a type of referred pain, meaning that the source of the pain differs from the location where the pain is felt. Primary ear pain is more common in children, whereas secondary (referred) pain is more common in adults.

Primary ear pain
The ear can be anatomically divided into the external ear, the external auditory canal, and the middle ear. Primary ear pain is most commonly caused by infection or injury to one of these parts of the ear.

Disorders of the external ear
Many conditions involving the external ear will be visible to the naked eye. Because the external ear is the most exposed portion of the ear, it is vulnerable to trauma or environmental exposures. Blunt trauma, such as a blow to the ear, can result in a hematoma, or collection of blood between the cartilage and perichondrium of the ear. These types of injuries are particularly common in contact sports such as wrestling and boxing. Environmental injuries include sunburn, frostbite, or contact dermatitis. Less common causes of external ear pain include :
 * Auricular Cellulitis: a superficial infection of the ear that may be precipitated by trauma, an insect bite, or ear piercing. Redness, swelling, and warmth of the ear develop rather quickly. Treatment includes antibiotics.
 * Perichondritis: infection of the perichondrium, or fascia surrounding the ear cartilage, which can develop as a complication of untreated auricular cellulitis. Perichondritis also presents with ear redness, swelling, and tenderness, but spares the earlobes because they do not contain cartilage. It is important to identify and treat perichondritis with antibiotics to avoid permanent ear deformities.
 * Relapsing polychondritis: a systemic inflammatory condition involving cartilage in many parts of the body. Multiple episodes of pain and inflammation of the ear cartilage, often involving both ears, are a common aspect of the condition. The severity and prognosis of the disease varies widely.

Otitis externa
Otitis externa, also known as “swimmer's’ ear, ” is a cellulitis of the external ear canal. 98% of cases of otitis externa in North America are caused by bacteria, and the most common causative organisms are Pseudomonas and Staph aureus. Risk factors include exposure to excessive moisture (e.g. from swimming or a warm climate) and disruption of the protective cerumen barrier, which can result from aggressive ear cleaning or placing objects in the ear. Common symptoms include itching, swelling of the ear canal, ear drainage, and pain with movement of the external ear.

Malignant otitis externa is a rare and potentially life-threatening complication of otitis externa in which the infection spreads from the ear canal into the surrounding skull base, hence becoming an osteomyelitis. It occurs largely in diabetic patients. It is very rare in children, though can be seen in immunocompromised children and adults. Pseudomonas is the most common causative organism. The pain tends to be more severe than in uncomplicated otitis externa, and laboratory studies often reveal elevated inflammatory markers (ESR and/or CRP). The infection may extend to cranial nerves, or rarely to the meninges or brain. Examination of the ear canal may reveal granulation tissue in the inferior canal. It is treated with several weeks of IV and oral antibiotics, usually fluoroquinolones.

Mechanical obstruction of the ear canal

 * Cerumen impaction: results in 12 million medical visits annually in the United States . Cerumen impaction may cause ear pain, but it can also prevent thorough examination of the ear and identification of an alternate source of pain.
 * Foreign body

Less common causes

 * Varicella zoster infection: resulting from virus reactivation that involving the ear. It can produce pain and visible vesicles within the ear canal and, when combined with facial paralysis due to facial nerve involvement, is called Ramsay Hunt syndrome.
 * Tumors: most commonly squamous cell carcinoma. Symptoms can resemble those of otitis externa, and should be considered if not improving on appropriate treatment.