Practice Essentials
Persistent idiopathic facial pain (PIFP), originally known as atypical facial pain, refers to pain along the territory of the trigeminal nerve that does not fit the classic presentation of other cranial neuralgias. [1, 2] The pain is usually of long duration, lasting most of the day (if not continuous), is unilateral, and is without autonomic signs or symptoms. It is described as a severe ache, crushing sensation, or burning sensation.
Signs and symptoms
The Headache Classification Subcommittee of the International Headache Society defines PIFP as follows: [3]
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Pain is in the face
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Pain is present daily and persists for all or most of the day
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Pain is confined at onset to a limited area on one side of the face and is deep and poorly localized
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In addition, the pain is not associated with sensory loss or other physical signs, with no abnormalities in laboratory or imaging studies
Diagnosis
PIFP is a diagnosis of exclusion.
Diagnostic imaging may be helpful. Magnetic resonance imaging (MRI) of the brain, with and without gadolinium contrast, is the modality of choice in this setting. Computed tomography (CT) of the brain with contrast has a lower yield than MRI does because it yields poorer resolution of the posterior fossa and cranial nerves.
Management
Medical treatment of PIFP is usually less satisfactory than medical treatment of other facial pain syndromes.
Anticonvulsants (antiepileptic drugs [AEDs]) and antidepressants (eg, tricyclic antidepressants [TCAs], selective serotonin reuptake inhibitors [SSRIs], and norepinephrine reuptake inhibitors [NeRIs]) are the mainstays of pharmacologic treatment. Narcotics may be appropriate if administered under careful supervision.
Background
Persistent idiopathic facial pain (PIFP), originally known as atypical facial pain, refers to pain along the territory of the trigeminal nerve that does not fit the classic presentation of other cranial neuralgias. [1, 2] The pain is usually of long duration, lasting most of the day (if not continuous), is unilateral, and is without autonomic signs or symptoms. It is described as a severe ache, crushing sensation, or burning sensation. Upon examination and workup, no abnormality is noted.
Within the group of chronic facial pain syndromes, PIFP represents a particular diagnostic challenge. Patients frequently are misdiagnosed or attribute their pain to a prior event, such as a dental procedure or facial trauma. Psychiatric symptoms of depression and anxiety are prevalent in this population, further compounding the diagnostic conundrum. Treatment of PIFP is typically less effective than that of other facial pain syndromes, and a multidisciplinary approach is required to address the many facets of this pain syndrome.
For patient education resources, see the Brain and Nervous System Center, as well as Trigeminal Neuralgia (Facial Nerve Pain).
Pathophysiology and Etiology
The Headache Classification Subcommittee of the International Headache Society defines persistent idiopathic facial pain (PIFP) as follows: [3]
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Pain is in the face
-
Pain is present daily and persists for all or most of the day
-
Pain is confined at onset to a limited area on one side of the face and is deep and poorly localized
-
In addition, the pain is not associated with sensory loss or other physical signs, with no abnormalities in laboratory or imaging studies
PIFP usually does not have a specific cause; however, injury of the trigeminal nerve proximally or distally may lead to this disorder. Demyelination, either central or peripheral, may initiate PIFP symptoms. Infectious causes should also be considered.
Epidemiology and Prognosis
Because of a lack of agreement on classification criteria, accurate figures on the frequency of persistent idiopathic facial pain (PIFP) are difficult to obtain. The estimated incidence has been estimated to be 1 case per 100,000 population (0.001%), though this number may be an underestimate. [4] A German study that included 3336 participants estimated the lifetime prevalence of PIFP to be 0.03%. [5]
PIFP mainly affects adults and is rare in children. [4] Overall, the disorder affects both sexes approximately equally, but more women than men seek medical care. [4]
For patients who do not respond to the available pharmacologic and nonpharmacologic therapies, the prognosis is poor.
