[Narcolepsy and alopecia areata: a new association?].

We here present three cases with Alopecia Areata and Narcolepsy, an association we believe to be hitherto undescribed. Narcolepsy is a low-frequency (0.5%) disorder. It is now accepted that the majority of patients with narcolepsy are DR2 positive. Alopecia Areata is a disease whose incidence in Caucasian population is between 0.05% and 1%. In both diseases there is a set of common data and the origins of the two diseases have been related to an autoimmunity mechanism. In both, a higher than normal incidence of diabetes has been recorded, together with a predominant HLA type pattern. We believe that this association is not casual although epidemiological studies are needed to test our working hypothesis.