Nummular headache: a gender-oriented perspective on a case series from the RegistRare Network.

Background: Nummular headache (NH) is a rare headache disorder characterized by a small, circumscribed painful area of the scalp. The description of many cases in the last years has supported its re-classification as a primary headache from the International Headache Society, moving it from its previous placement in the Appendix of the International Criteria of Headache Disorders.

Methods: Data were collected from a retro-prospective observational study about rare headaches promoted by the RegistRare Network, a collaborative group of seven Italian Headache Centres. According to the gender-biased profile of certain primary headaches, we have looked further NH patients from a gender perspective.

Results: Nineteen NH patients (11 men, 8 women) have been enrolled in the study. Headache onset was at 39 years and preceded approximately 8 years the diagnosis. No clinically evident differences between men and women have been found, including treatment prescriptions and headache resolution. Of note, the mean time from the onset of NH to the first visit in a Headache Centre was longer in men, compared with women (13.5 vs. 0.9 years). NH attacks were efficaciously treated with nonsteroidal anti-inflammatory drugs in 60% of patients receiving treatment. Headache prophylaxis with pregabalin and amitriptyline has been reported as effective in 40% and 67% of the treated patients, respectively.

Conclusions: NH is a primary headache clinically heterogeneous in terms of temporal patterns and pain characteristics. Further research is needed to investigate the existence of male and female phenotypes, by clarifying whether it may be relevant for therapeutic purposes.