The term atypical facial pain was first introduced by Frazier and Russell in 1924. It has since been renamed persistent idiopathic facial pain (PIFP). PIFP refers to pain along the territory of the trigeminal nerve that does not fit the classic presentation of other cranial neuralgias.1 The duration of pain is usually long, lasting most of the day (if not continuous). Pain is unilateral and 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.
The International Headache Society defines PIFP as follows (Headache Classification Subcommittee of the International Headache Society, 2004):
Within the group of chronic facial pain syndromes, PIFP represents a 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 and compound the diagnostic conundrum. Treatment is less effective than in other facial pain syndromes and requires a multidisciplinary approach to address the many facets of this pain syndrome.
The following are examples of common facial pain or headache syndromes, along with some of the classic characteristics:
Trigeminal neuralgia
Postherpetic neuralgia
TMJ syndrome
Cluster headache
Cluster-tic syndrome
SUNCT syndrome
Jabs and jolts syndrome, primary stabbing headache, or ice-pick headache
Raeder syndrome
Thalamic pain syndrome
Hemicrania continua
Migraine