13.11 Persistent idiopathic facial pain (PIFP)

Previously used term:
Atypical facial pain.

Persistent facial and/or oral pain, with varying presentations but recurring daily for more than two hours per day over more than three months, in the absence of clinical neurological deficit.

Diagnostic criteria:
A. Facial and/or oral pain fulfilling criteria B and C
B. Recurring daily for >2 hr per day for >3 months
C. Pain has both of the following characteristics:

    1. poorly localized, and not following the distribution of a peripheral nerve
    2. dull, aching or nagging quality

D. Clinical neurological examination is normal
E. A dental cause has been excluded by appropriate investigations
F. Not better accounted for by another ICHD-3 diagnosis.

A wide variety of words are used to describe the character of 13.11 Persistent idiopathic facial pain (PIFP) but it is most often depicted as dull, nagging or aching. It can have sharp exacerbations, and is aggravated by stress. Pain may be described as either deep or superficial. With time, it may spread to a wider area of the craniocervical region.

13.11 Persistent idiopathic facial pain (PIFP) may be comorbid with other pain conditions such as chronic widespread pain and irritable bowel syndrome. In addition, it presents with high levels of psychiatric comorbidity and psychosocial disability.

A continuum seems to exist from 13.11 Persistent idiopathic facial pain (PIFP) induced by insignificant trauma to Painful post-traumatic trigeminal neuropathy caused obviously by significant insult to the peripheral nerves. 13.11 Persistent idiopathic facial pain (PIFP) may originate from a minor operation or injury to the face, maxillae, teeth or gums but persist after healing of the initial noxious event and without any demonstrable local cause. However, psychophysical or neurophysiological tests may demonstrate sensory abnormalities.

The term atypical odontalgia has been applied to a continuous pain in one or more teeth or in a tooth socket after extraction, in the absence of any usual dental cause. This is thought to be a subform of 13.11 Persistent idiopathic facial pain (PIFP) although it is more localized, the mean age at onset is younger and genders are more balanced. Based on the history of trauma, atypical odontalgia may also be a subform of Painful post-traumatic trigeminal neuropathy. These subforms, if they exist, have not been sufficiently studied to propose diagnostic criteria.