A new study finds that up to 10% of people with headaches also have facial pain. The study is published in the August 21, 2019, online issue of Neurology, the medical journal of the American Academy of Neurology.

"Facial pain has not been well recognized as a symptom of headache, and some people end up waiting a long time for a proper diagnosis and treatment," said study author Arne May, MD, PhD, of the University of Hamburg in Germany. "This study shows that facial pain is not uncommon, and for many people their pain occurs mainly in the face, not the head."

The study involved 2,912 people with primary headaches, which are headaches not due to another condition and include migraine and cluster headache. Participants were asked to fill out questionnaires about their headaches and any facial pain. People with dental problems that could explain the facial pain were not included in the study.

Of the study participants, 291 people, or 10%, had facial pain. Only 2%, or 44 of the 1,935 people with migraine, had facial pain. Of those, 41% experienced pain predominantly in the face. Among people with cluster headache, 15%, or 42 of 283 people, had facial pain. Of those, 31% had pain mainly in the face.

Among the 20 people with paroxysmal hemicrania, a rare type of headache with severe, often short attacks on one side of the head, 45% had facial pain. Facial pain affected 21% of the 42 people with hemicrania continua, another rare type of headache with continuous pain that varies in severity.

In another rare type of headache, called short-lasting unilateral neuralgiform headache, 20% of the 15 people in the study had facial pain. This type of headache involves very frequent attacks on one side of the head.

The researchers also reported on six people who had constant facial pain on one side of the head only in addition to facial pain attacks lasting 10 to 30 minutes and occurring several times a day. Dr. May said this type of pain syndrome has not been described before and proposed calling it constant unilateral facial pain with added attacks.

"For a better understanding of these types of facial pain and ultimately for the development of treatments, it's crucial that we understand more about facial pain and whether it is the same disease as the headache, but showing up in a different place, or whether they are two different syndromes," Dr. May said.

A limitation of the study was that participants were asked about their headaches in the past and they may not remember all symptoms. Also, facial pain may not have been mentioned by participants to their doctors nor asked about by the doctors, so the percentage of people with facial pain may have been underestimated, May said.