Nummular headache update.

Nummular headache is characterized by head pain exclusively felt in a rounded or elliptical area, typically 1 to 6 cm in diameter. The pain remains confined to the same symptomatic area, which does not change in shape or size with time. The symptomatic area may be localized in any part of the head but mostly in the parietal region. Rarely, the disorder may be multifocal, each symptomatic area keeping all the characteristics of nummular headache. The pain is generally mild or moderate, commonly described as oppressive or stabbing, and lasting minutes, hours, or days, with a remitting or unremitting pattern. Superimposed on the baseline pain, there may be spontaneous or triggered exacerbations. During and between symptomatic periods, the affected area may show variable combinations of hypoesthesia, dysesthesia, paresthesia, tenderness, and trophic changes. Nummular headache emerges as a primary disorder with a clear-cut clinical picture developed in a unique topography.