Red Ear Syndrome
Atlas of Uncommon Pain Syndromes, Chapter 18, 46-47
ICD-9 CODE 350.1
ICD-10 CODE G50.0
The Clinical Syndrome
Red ear syndrome is an uncommon primary pain disorder thought to be a variant of one of a group of three headache syndromes known as the trigeminal autonomic cephalgias ( Table 18-1 ). Whether red ear syndrome is in fact a distinct pain syndrome resulting from auriculo-autonomic dysfunction or simply a constellation of symptoms that occurs on a continuum along with the other trigeminal autonomic cephalgias is a point of ongoing debate among headache and pain management specialists. As with most headache and facial pain syndromes, the exact cause of the pain of red ear syndrome is unknown; however, the pathogenesis of this uncommon cause of head and face pain is thought to be dysfunction of the trigeminal autonomic reflex. The rapid onset of ear redness and associated pain may be caused by an antidromic release of vasoactive peptides from the terminal afferent fibers of the third cervical nerve root, which provides sensory innervations to the pinna of the ear.
TABLE 18-1
The Trigeminal Autonomic Cephalgias
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As its name implies, the pathognomonic finding of red ear syndrome is in fact a unilateral red ear ( Figure 18-1 ). This redness involves the entire ear, including the pinna, and is associated with neuralgia-like pain reminiscent of sudden unilateral neuralgiform conjunctival injection tearing (SUNCT) headache (see Chapter 7 ). The pain and erythema associated with red ear syndrome have a rapid onset to peak, with attacks lasting 15 seconds to 5 minutes and the frequency of attacks ranging from 20 to 200 attacks per day. In some patients, these attacks can be triggered by sensory stimulation of the affected area, such as when brushing the hair. Although in many ways similar to SUNCT headache (i.e., unilateral, rapid onset to peak, short duration of attacks, pain-free periods between attacks), many dissimilarities also exist, including the location and pronounced autonomic phenomenon manifested by the red ear.
Red ear syndrome is characterized by the complaint of severe paroxysms of sudden onset of unilateral ear redness associated with ipsilateral ear pain.
Signs and Symptoms
Patients with red ear syndrome present with the complaint of severe paroxysms of sudden onset of unilateral ear redness associated with pain involving the ipsilateral ear. The pain is neuralgiform in quality and severe to excruciating in intensity. Like trigeminal neuralgia, the pain of red ear syndrome rarely switches sides. Red ear syndrome occurs slightly more frequently in males. It can occur at any age, with a peak incidence in the fifth decade.
Testing
Magnetic resonance imaging (MRI) of the brain provides the clinician with the best information regarding the cranial vault and its contents. MRI is highly accurate and helps identify abnormalities that may put the patient at risk for neurological disasters secondary to intracranial and brainstem pathology, including tumors and demyelinating disease. Magnetic resonance angiography (MRA) also may be useful in helping identify aneurysms that may be responsible for the patient’s neurological findings. In patients who cannot undergo MRI, such as patients with pacemakers, computed tomography (CT) is a reasonable second choice. Radionuclide bone scan and plain radiography are indicated if a fracture or bony abnormality such as metastatic disease is considered in the differential diagnosis.
Screening laboratory tests consisting of complete blood cell count, erythrocyte sedimentation rate, and automated blood chemistry should be performed if the diagnosis of red ear syndrome is in question. Additional testing to rule out collagen-vascular disease is indicated if polychondritis is suspected.
Differential Diagnosis
Red ear syndrome is a clinical diagnosis supported by a combination of clinical history, normal physical examination, radiography, and MRI. Pain syndromes that may mimic red ear syndrome include erythromelalgia of the ear, polychondritis, cluster headache, temporal arteritis, trigeminal neuralgia, demyelinating disease, primary stabbing headache, SUNCT, and chronic paroxysmal hemicranias. However, because of the overlapping features of all headache and facial pain syndromes, red ear syndrome easily can be mistaken for another type of headache or facial pain. Trigeminal neuralgia is more common and is characterized by trigger areas and tic-like movements. Demyelinating disease is generally associated with other neurological findings, including optic neuritis and other motor and sensory abnormalities. The pain of chronic paroxysmal hemicrania lasts much longer than the pain of red ear syndrome.
Treatment
The treatment of red ear syndrome is analogous to the treatment of trigeminal neuralgia, although the pharmacological management of this uncommon headache disorder is disappointing. The use of anticonvulsants such as lamotrigine and gabapentin represents a reasonable starting point. High-dose steroids tapered over 10 days also have been anecdotally reported to provide relief. For patients who do not respond to these treatments, a few case reports suggest that daily ipsilateral C2-C3 facet joint blocks with local anesthetic and steroid may provide relief of both the pain and the autonomic dysfunction. Underlying sleep disturbance and depression associated with the pain of red ear syndrome are best treated with a tricyclic antidepressant compound, such as nortriptyline, which can be started at a single bedtime dose of 25 mg.
Complications and Pitfalls
Failure to diagnose red ear syndrome correctly may put the patient at risk if intracranial pathology or demyelinating disease, which may mimic the clinical presentation of red ear syndrome, is overlooked. MRI is indicated in all patients thought to have red ear syndrome. A careful evaluation of the ear to rule out localized pathological conditions is also indicated, as is laboratory testing for collagen-vascular disease if polychondritis is suspected.
CLINICAL PEARLS
Given the poor response to treatment with drugs traditionally used to treat trigeminal neuralgia, facet block of the ipsilateral C2-C3 facet joints with local anesthetic and steroids should be considered in patients thought to have red ear syndrome. Given the uncommon nature of this headache syndrome and its overlap with the other trigeminal autonomic cephalgias and other more serious forms of intracranial pathological conditions such as tumors and vascular abnormalities, red ear syndrome must remain a diagnosis of exclusion. All patients thought to have red ear syndrome require MRI of the brain with and without gadolinium contrast material and thorough otic and neurological evaluation. Cervical facet block should be performed only by clinicians familiar with the regional anatomy.
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