These include increased temperature and tenderness of the mucosa in the affected area, which is otherwise normal in every regard.Patient often reports symptoms of paresthesia, pain, and throbbing. Physical examination may be normal, but hypoesthesia, hyperesthesia, and allodynia may be found. The features of atypical facial pain can be considered according to the Socrates pain assessment method (see table). Causes
Health care associated
Sometimes dental treatment or surgical procedures in the mouth appear to precede the onset of AFP, or sometimes persons with AFP will blame clinicians for their pain. Organic disease
Many persons with AFP blame organic disease for their pain.Research in individuals with AFP showed that there is increased cerebral activity (demonstrated during positron emission tomography), possibly suggesting that there is an overactive alerting mechanism to peripheral stimuli. It has been theorized that this can trigger neuropeptides to be released, and the formation of free radicals (capable of damaging cells), the release of eicosanoids (e.g. prostaglandins). There is some suggestion that AFP is an early form of trigeminal neuralgia.Pain may be referred from other parts of the head or other parts of the body to cause facial pain. Nowhere in the body is referred pain more well illustrated than in the face, and this is due to the richly and complexly innervated nature of the head and neck. "Neuralgia-inducing cavitational osteonecrosis"
Neuralgia-inducing cavitational osteonecrosis (NICO) is a controversial term, and it is questioned to exist by many.
Atypical facial pain (AFP) is a type of chronic facial pain which does not fulfill any other diagnosis. There is no consensus as to a globally accepted definition, and there is even controversy as to whether the term should be continued to be used. Both the International Headache Society (IHS) and the International Association for the Study of Pain (IASP) have adopted the term persistent idiopathic facial pain (PIFP) to replace AFP. In the 2nd Edition of the International Classification of Headache Disorders (ICHD-2), PIFP is defined as "persistent facial pain that does not have the characteristics of the cranial neuralgias ... and is not attributed to another disorder." However, the term AFP continues to be used by the World Health Organizations 10th revision of the International Statistical Classification of Diseases and Related Health Problems and remains in general use by clinicians to refer to chronic facial pain that does not meet any diagnostic criteria and does not respond to most treatments.The main features of AFP are: no objective signs, negative results with all investigations/ tests, no obvious explanation for the cause of the pain, and a poor response to attempted treatments. AFP has been described variably as a medically unexplained symptom, a diagnosis of exclusion, a psychogenic cause of pain (e.g. a manifestation of somatoform disorder), and as a neuropathy. AFP is usually burning and continuous in nature, and may last for many years.