Persistent Idiopathic Facial Pain (PIFP) is a disease characterized by chronic (persistent), unilateral or bilateral pain that occurs in the facial region without an obvious cause.
This condition is one of the most difficult facial pain types to diagnose for both patient and physician.

Facial pains are commonly seen due to reasons such as dental problems, sinusitis, trigeminal neuralgia. However, persistent idiopathic facial pain is a special clinical picture in which none of these causes can be detected.
Pain is generally of dull, burning, or stabbing quality and can last for weeks, months, or even years.

This disease is included in the International Classification of Headache Disorders (ICHD-3) under the heading “Persistent Idiopathic Facial Pain” and is also known as “atypical facial pain.”

Importance of Persistent Idiopathic Facial Pain

Persistent idiopathic facial pain is a complex condition involving neurology and dentistry disciplines in terms of both diagnosis and treatment. Diagnosis can take on average months or even years because most patients initially apply to different branches for dental, otolaryngology, or sinus-originated pains.

Early diagnosis and multidisciplinary approach are of great importance to prevent unnecessary tooth extractions and invasive procedures. With appropriate treatment, pain can be controlled and patients’ quality of life significantly improves.

What is Persistent Idiopathic Facial Pain?

Persistent Idiopathic Facial Pain (PIFP) is a chronic facial pain syndrome defined in medicine as “Persistent Idiopathic Facial Pain (PIFP)” with no obvious cause.
This condition is different from classic trigeminal neuralgia. Pain is generally in the form of burning, aching, or pressure sensation. It is not electric shock-like as in trigeminal neuralgia.

Persistent idiopathic facial pain mostly starts on one side of the face and can last for days, weeks, or months. There may be fluctuations in pain severity from time to time, but it is generally continuous in character.

This condition is also called “atypical facial pain” or “atypical trigeminal neuralgia.”
The term “idiopathic” means the absence of an underlying structural or neurological cause. Therefore, the diagnosis and treatment process can be quite challenging for both patients and physicians.

What Causes Persistent Idiopathic Facial Pain?

The exact cause of Persistent Idiopathic Facial Pain (PIFP) is not fully known.
However, research shows that this condition occurs as a result of complex interaction of neuropathic, vascular, hormonal, and psychological factors.
These factors are explained in detail below:

1. Neuropathic Factors (Nerve-Originated Causes)

Damage or dysfunction in the branches of the trigeminal nerve, which is the most important sensory nerve in the facial region, is accepted as the main cause of persistent idiopathic facial pain.

These damages can develop after the following situations:

• Microvessel compression or microvascular decompression
• Nerve irritation after dental or jaw surgery
• Infections or traumas
• Demyelination in nerve fibers (damage to protective layer)

In this situation, nerve cells can perceive normal sensations as pain signals.
As a result, spontaneous pain signals occur even without external stimulus, leading to chronic neuropathic pain picture.

2. Vascular Factors (Vessel-Originated Causes)

Blood circulation disorders in the facial region can play an important role in the persistence of pain.
Especially microvascular ischemia (decreased blood flow in small vessels) or vasospasm (vessel contractions) disrupt nerve oxygenation and trigger pain signals.

This mechanism is more pronounced in individuals with migraine history.
The interaction of vascular and neurological systems can make persistent idiopathic facial pain permanent by increasing nerve sensitivity.

3. Hormonal and Psychogenic Factors

Its more frequent occurrence in women suggests that hormonal effects play a role in the disease.
Especially changes in estrogen levels during menopause can increase susceptibility to chronic pain by lowering the pain threshold.

Additionally, psychological factors such as stress, anxiety, and depression can also strengthen pain perception.
In these situations, the brain interprets normal sensory signals as pain and the pain cycle continues.

Therefore, in the treatment of persistent idiopathic facial pain, not only medication but also psychological support and stress management are of great importance.

In summary:

• Trigeminal nerve damage → Development of neuropathic pain
• Microvascular disorders → Circulation and oxygenation insufficiency
• Hormonal changes → Lowering of pain threshold
• Stress and anxiety → Increased pain perception

What Are the Symptoms of Persistent Idiopathic Facial Pain?

Persistent Idiopathic Facial Pain (PIFP) symptoms are of great importance for correct diagnosis of the disease. This pain type is generally continuous, unilateral, and chronic in character, but over time its severity may increase or show an undulating course.

Symptoms can be examined under three main headings:

1. Main Pain Characteristics

Persistent idiopathic facial pain, unlike classic trigeminal neuralgia, is described not as electric shock-like, but more as burning, aching, throbbing, or pressure sensation.

Typical characteristics of pain:

• Generally starts on one side of the face, rarely can be bilateral.
• Felt in lower or upper jaw, cheek, forehead, or around the eye.
• Pain continues throughout the day, its intensity sometimes increases.
• Stress, cold weather, fatigue, or emotional tension can trigger pain.

This pain type is one of the most resistant among chronic facial pain syndromes.

2. Accompanying Symptoms

Symptoms accompanying pain may vary depending on the involvement of the nervous system and autonomic system:

• Numbness or tingling sensation in the face
• Hypersensitivity to touch (allodynia) or decreased sensitivity (hypoesthesia)
• Eye tearing, nasal discharge, slight swelling or warmth sensation in the face
• Increase in pain during stressful or fatigue periods

In some patients, symptoms may also be affected by weather changes similar to migraine.

3. Functional and Psychological Impact

Persistent idiopathic facial pain can seriously affect patients’ quality of life.
Even daily simple activities can increase pain:

• Pain can be triggered during chewing, speaking, or smiling.
• Due to continuous pain, sleep quality deteriorates, appetite decreases, social isolation can develop.
• Prolonged pain can lead to psychological problems such as anxiety and depression over time.

Therefore, addressing not only the physical but also the emotional aspect of the disease is important for treatment success.

In summary:

• Continuous, burning, or aching type pain
• Discomfort pronounced on one side of the face
• Numbness, tingling, or autonomic symptoms
• Chronic pain picture affecting daily activities and mood

How is Persistent Idiopathic Facial Pain Diagnosed?

Persistent idiopathic facial pain is diagnosed by detailed neurological examination and imaging methods. It is diagnosed after other causes are excluded according to International Classification of Headache Disorders (ICHD-3) diagnostic criteria.

Persistent Idiopathic Facial Pain (PIFP) diagnosis is made by careful clinical evaluation and exclusion of other facial pain causes. This diagnosis is supported by detailed history taking, neurological examination, and imaging studies if necessary.

1. Clinical Evaluation

The first step in diagnosis is detailed inquiry of the patient’s pain history.
The physician evaluates the following elements:

• Onset, duration, and severity of pain
• Localization of pain (e.g., cheek, jaw, forehead region)
• Triggering factors (stress, cold weather, chewing, speaking)
• Accompanying symptoms (numbness, tingling, eye tearing, etc.)

Neurological examination includes testing the sensory functions of the three branches (V1, V2, V3) of the trigeminal nerve.
Changes in touch, pain, and temperature sensations are investigated.
Additionally, other cranial nerves are also examined to exclude possible systemic or central nervous system diseases.

2. Imaging Methods

Imaging is very important for supporting diagnosis and excluding organic causes.

• Brain Magnetic Resonance Imaging (MRI):
  The brain, brainstem, and structures around the trigeminal nerve are examined in detail.
  Tumor, vascular compression, multiple sclerosis, or nerve root pathologies are excluded.
• MR Angiography:
  Vascular malformations and the relationship between the trigeminal nerve and vessels are evaluated.
  Especially microvascular compression or nerve-artery contact is important in surgical treatment planning.

Through these imaging techniques, other causes such as trigeminal neuralgia, sinus diseases, or dental-originated pains are distinguished.

3. Laboratory Tests

In some cases, systemic diseases need to be excluded.
For this:

• Complete blood count,
• Inflammatory markers (CRP, ESR),
• Autoimmune tests (ANA, anti-dsDNA)

These tests help rule out accompanying conditions such as Systemic Lupus Erythematosus (SLE), multiple sclerosis (MS), or vasculitis.

International Classification of Headache Disorders (ICHD-3) Diagnostic Criteria – 13.12 Persistent idiopathic facial pain (PIFP)

According to the International Classification of Headache Disorders (ICHD-3, code 13.12), diagnosis is made with the following criteria:

A. Facial pain occurring every day or almost every day for at least 3 months.
B. Pain is generally located on one side of the face and is not limited to trigeminal nerve distribution.
C. Pain can be constant or fluctuating, felt as burning, aching, pressure-like.
D. There is no marked sensory loss on neurological examination.
E. No structural cause explaining the pain is detected in imaging and other tests.

These criteria enable differentiation of Persistent Idiopathic Facial Pain from other neuropathic pain syndromes (e.g., trigeminal neuralgia, postherpetic neuralgia).

Differential Diagnosis

Persistent Idiopathic Facial Pain (PIFP) can often be confused with similar facial pain syndromes.
Therefore, differential diagnosis is of great importance for making correct diagnosis. Each disease has its own characteristics in terms of pain duration, type, triggers, and accompanying symptoms.

The following conditions are mainly included in the differential diagnosis of PIFP:

1. Trigeminal Neuralgia

Trigeminal neuralgia is characterized by sudden, electric shock-like, seconds-long pains on one side of the face.
These pains occur upon touching trigger points and progress in attacks.
Whereas Persistent Idiopathic Facial Pain is a more continuous and dull quality pain, felt continuously, not in attacks.

2. Atypical Facial Pain

In ICHD-3 classification, the term “Persistent Idiopathic Facial Pain” is used instead of the old name atypical facial pain.
Therefore, these two terms generally refer to the same condition.
However, some physicians use the term “atypical facial pain” for mixed clinical pictures or psychogenic pains.

3. Temporomandibular Joint (TMJ) Dysfunction

TMJ-originated pains generally increase with jaw movements and click sound from the joint may be heard.
Pain becomes pronounced during chewing and is felt in the preauricular region.
In PIFP, pain is not so movement-dependent and has a more widespread distribution.

4. Migraine and Cluster Headache

Migraine pain is generally on one side of the head, throbbing in character, and progresses with light and sound sensitivity.
Cluster headache is characterized by intense around the eye, short-duration but very severe attacks.
In both conditions, pain shows episodic course (occurs at intervals), whereas persistent idiopathic facial pain is continuous.

5. Neoplasms (Tumors) and Nerve Compressions

Tumors originating from the brainstem or trigeminal nerve can rarely cause facial pain.
In these cases, there are generally additional neurological findings such as sensory loss, muscle weakness, or unilateral reflex loss.
Therefore, performing brain MRI imaging to exclude the possibility of tumor is mandatory.

What is the Treatment of Persistent Idiopathic Facial Pain?

In the treatment of persistent idiopathic facial pain, medications, nerve blocks, psychological support, and lifestyle modifications are applied together. Treatment should be planned individually.

Persistent Idiopathic Facial Pain (PIFP) treatment requires a multifaceted approach.
The goal is to reduce pain, increase quality of life, and prevent chronification of the disease.
The treatment plan is individualized for each patient and generally includes a combination of medication therapy, invasive interventions, and supportive approaches.

1. Pharmacological (Medication) Treatment

Medication therapy forms the basis of persistent idiopathic facial pain.
Due to the neuropathic character of pain, the most effective group is anticonvulsants (antiepileptics) and tricyclic antidepressants.

Anticonvulsants:

• Carbamazepine, gabapentin, pregabalin, and lamotrigine reduce transmission of pain signals.
• Started at low dose, gradually increased according to patient’s response.
• These medications are also effective in trigeminal nerve-originated pains.

Tricyclic Antidepressants:

• Amitriptyline and nortriptyline correct depression and sleep disorders in addition to chronic neuropathic pain.
• These medications balance serotonin and noradrenaline levels that alter pain perception.

Topical Treatments:

• Creams containing lidocaine or capsaicin can be applied locally to painful areas of the face.
• Provide an important alternative in patients who cannot use systemic medication.

2. Invasive Treatment Methods

Invasive methods come into play in patients who do not respond to medication therapy or whose pain is very severe:

• Trigeminal nerve block:
  Temporary pain relief is provided with local anesthetic or steroid injection.
• Radiofrequency ablation and glycerol injection:
  It is aimed to stop pain signal transmission by targeting nerve endings.
• Microvascular decompression surgery:
  Permanent relief can be achieved by surgically removing vascular structures compressing the trigeminal nerve.
  It is an effective option especially in cases where vessel contact is detected.

3. Supportive and Complementary Treatments

Psychological and physical support approaches are of great importance in chronic pain management.

• Physiotherapy and relaxation exercises relax facial and neck muscles.
• Acupuncture, meditation, and breathing exercises can increase the nervous system’s pain threshold.
• Psychological support and cognitive behavioral therapy (CBT) make it easier to cope with stress and anxiety created by chronic pain.

These methods are part of a holistic approach in pain management.

4. Prognosis and Follow-up

The course of persistent idiopathic facial pain varies from person to person.
Early diagnosis and regular follow-up are the most important factors determining long-term outcomes.

• Regular neurology check-ups help adjust medication doses and monitor side effects.
• Lifestyle modifications (adequate sleep, stress management, healthy nutrition) increase treatment success.
• Exercise and low-stress lifestyle raise the pain threshold and reduce the risk of disease recurrence.

In the long term, pain control can be achieved in patients who comply with treatment and quality of life improves significantly.

Frequently Asked Questions

1. What is the Difference Between Persistent Idiopathic Facial Pain and Trigeminal Neuralgia?

Although Persistent Idiopathic Facial Pain (PIFP) and trigeminal neuralgia are often confused, these two diseases are different from each other.

• Trigeminal neuralgia generally progresses with short-duration, sudden, “electric shock” type attacks.
• Persistent idiopathic facial pain, however, is continuous or nearly continuous, burning or aching.

While in trigeminal neuralgia pain generally starts upon touching trigger points, there are no such distinct triggers in PIFP. Additionally, while there may be pain-free periods in trigeminal neuralgia, pain shows continuity in PIFP.

2. Does This Disease Completely Heal, or Does It Last a Lifetime?

Persistent idiopathic facial pain is a chronic disease; however, with correct treatment, symptoms can be controlled.
Although complete recovery is not possible in every patient, pain can be greatly reduced with medication therapy, psychological support, and lifestyle modifications.

While some patients experience remission (recovery) periods, some may need long-term treatment. Thanks to modern treatment methods, patients can largely return to their daily lives.

3. Which Doctor Should I Consult for This Disease?

This disease is of neurological origin. Therefore, the first specialty to consult should be neurology.

The neurology specialist makes the diagnosis with necessary examination and imaging tests.
In some cases, consultation with a pain treatment specialist or neurosurgery may also be needed. Multidisciplinary treatment approach gives the most successful results.

4. Is This Disease Genetic, Does It Run in Families?

The exact genetic cause of persistent idiopathic facial pain has not yet been determined.
The vast majority of cases are sporadic, that is, they occur coincidentally without familial inheritance.

However, the likelihood of occurrence may be slightly higher in families with a history of neurological diseases such as migraine and epilepsy. The disease is not contagious. In cases where genetic predisposition is suspected, medical genetic counseling may be beneficial.

5. Is This Disease More Common in Women or Men?

Scientific studies show that persistent idiopathic facial pain is seen 2 to 3 times more frequently in women. It is thought that hormonal factors play a role behind this situation.

Especially during menopause, fluctuations in estrogen levels can prepare the ground for the disease to emerge by lowering the pain threshold. However, this condition is not exclusive to women — the disease can be seen in both genders and at any age.