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
The International Headache Society (IHS) is a London-based charity membership organisation that was founded in 1981 for those with a professional commitment to helping people affected by headache disorders and facial pains. In 1994, the IHS was ...
(IHS) and the
International Association for the Study of Pain
The International Association for the Study of Pain (IASP) is an international learned society promoting research, education, and policies for the understanding, prevention, and treatment of pain. IASP was founded in 1973 under the leadership of ...
(IASP) have adopted the term persistent idiopathic facial pain (PIFP) to replace AFP. In the 2nd Edition of the
International Classification of Headache Disorders
The International Classification of Headache Disorders (ICHD) is a detailed hierarchical classification of all headache-related disorders published by the International Headache Society. It is considered the official classification of headache ...
(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 Organization
The World Health Organization (WHO) is a specialized agency of the United Nations responsible for international public health. The WHO Constitution states its main objective as "the attainment by all peoples of the highest possible level of h ...
diagnosis of exclusion
A diagnosis of exclusion or by exclusion (''per exclusionem'') is a diagnosis of a medical condition reached by a process of elimination, which may be necessary if presence cannot be established with complete confidence from history, examination or ...
, a
psychogenic
A psychogenic effect is one that originates from the brain instead of other physical organs (i.e. the cause is psychological rather than physiological) and may refer to:
*Psychogenic pain
*Psychogenic disease
*Psychogenic amnesia
*Psychogenic cou ...
neuropathy
Peripheral neuropathy, often shortened to neuropathy, is a general term describing disease affecting the peripheral nerves, meaning nerves beyond the brain and spinal cord. Damage to peripheral nerves may impair sensation, movement, gland, or o ...
. AFP is usually burning and continuous in nature, and may last for many years. Depression and
anxiety
Anxiety is an emotion which is characterized by an unpleasant state of inner turmoil and includes feelings of dread over anticipated events. Anxiety is different than fear in that the former is defined as the anticipation of a future threat wh ...
are often associated with AFP, which are either described as a contributing cause of the pain, or the emotional consequences of suffering with unrelieved, chronic pain. For unknown reasons, AFP is significantly more common in middle aged or elderly people, and in females.
Atypical odontalgia (AO) is very similar in many respects to AFP, with some sources treating them as the same entity, and others describing the former as a sub-type of AFP. Generally, the term AO may be used where the pain is confined to the teeth or gums, and AFP when the pain involves other parts of the face. As with AFP, there is a similar lack of standardization of terms and no consensus regarding a globally accepted definition surrounding AO. Generally definitions of AO state that it is pain with no demonstrable cause which is perceived to be coming from a tooth or multiple teeth, and is not relieved by standard treatments to alleviate dental pain.
Depending upon the exact presentation of atypical facial pain and atypical odontalgia, it could be considered as
craniofacial Craniofacial (''cranio-'' combining form meaning head or skull + ''-facial'' combining form referring to the facial structures grossly) is an adjective referring to the parts of the head enclosing the brain and the face.
The term is typically used ...
pain or
orofacial pain
Orofacial pain is a general term covering any pain which is felt in the mouth, jaws and the face. Orofacial pain is a common symptom, and there are many causes.
Orofacial Pain (OFP) is the specialty of dentistry that encompasses the diagnosis, ma ...
. It has been suggested that, in truth, AFP and AO are
umbrella term
In linguistics, semantics, general semantics, and ontologies, hyponymy () is a semantic relation between a hyponym denoting a subtype and a hypernym or hyperonym (sometimes called umbrella term or blanket term) denoting a supertype. In other wor ...
s for a heterogenous group of
misdiagnosed
A medical error is a preventable adverse effect of care ("iatrogenesis"), whether or not it is evident or harmful to the patient. This might include an inaccurate or incomplete diagnosis or treatment of a disease, injury, syndrome, behavior, i ...
or not yet fully understood conditions, and they are unlikely to each represent a single, discrete condition.
Signs and symptoms
Some sources list some non-specific signs that may be associated with AFP/AO. These include increased temperature and tenderness of the
mucosa
A mucous membrane or mucosa is a membrane that lines various cavities in the body of an organism and covers the surface of internal organs. It consists of one or more layers of epithelial cells overlying a layer of loose connective tissue. It is ...
in the affected area, which is otherwise normal in every regard.
Patient often reports symptoms of
paresthesia
Paresthesia is an abnormal sensation of the skin (tingling, pricking, chilling, burning, numbness) with no apparent physical cause. Paresthesia may be transient or chronic, and may have any of dozens of possible underlying causes. Paresthesias ar ...
,
pain
Pain is a distressing feeling often caused by intense or damaging stimuli. The International Association for the Study of Pain defines pain as "an unpleasant sensory and emotional experience associated with, or resembling that associated with, ...
, and
throbbing
{{Short pages monitor None of the persons reported that surgery was beneficial, and in many cases the pain was worsened by surgery. The article cited as the source of this information was withdrawn from publication, saying the information was out of date and not meeting Cochrane methodological standards.
It has been suggested that the onset of chronic facial pain will likely be a life changing development for those affected.
Epidemiology
AFP is sometimes described as being fairly common, and one estimated prevalence is about 1–2% of the general population. However, the IASP described PIFP as being rare, less common than trigeminal neuralgia (which has a prevalence of about 0.01–0.3% in the general population), and possessing no available epidemiologic data for estimated prevalence in the general population. The predominant age group is 30–50, and females are more often affected than males, with most reports stating that about 80% of people with AFP are female.