PMC

Anatomical distribution of pain in 4 study groups: OPPERA case–control study of facial pain. Color coding signifies location and proportion of subjects reporting ≥1 headache during the preceding 30 days or reporting pain at any of 35 noncraniofacial locations that had lasted ≥1 day during the preceding 3 months. Subjects are stratified according to the presence or absence of facial pain (classified as ≥5 days per month for ≥6 of the preceding 12 months) and type of pain symptom cluster: global symptoms or nonglobal symptoms. (A) Nonfacial pain controls, nonglobal symptoms (n = 739); (B) nonfacial pain controls, global symptoms (n = 124); (C) facial pain cases, nonglobal symptoms (n = 140); and (D) facial pain cases, global symptoms (n = 262).