The Red Ear syndrome (RES) is an intriguing syndrome originally described for the first time nearly 20 years ago. RES is characterized by unilateral/bilateral episodes of pain and burning sensation of the ear, associated with ipsilateral erythema. RES episodes are indeed isolated in some patients, but they can occur in association with primary headaches, including in particular migraine in the developmental age. Although the underlying pathophysiological mechanisms are still uncertain, in the recent years the described comorbidities have aroused increasing interest because of possible clinical implications. Moreover, RES seems to be more often associated with clinical features of migraine partially provoked by the involvement of the parasympathetic system. This clinical association has shed new light on the pathophysiology of RES, supporting the hypothesis of a shared pathophysiological background, for example, through the activation of the trigeminal autonomic reflex. Current therapies of RES will be also discussed. Finally, we will resume the more controversial aspects of this relatively new and probably underestimated neurological syndrome.
Keywords: Cranial autonomic symptoms; Erythromelalgia; Idiopathic red ear syndrome; Migraine; Parasympathetic system; Primary headaches; Red ear; Red ear syndrome; Secondary red ear syndrome; Trigeminal autonomic cephalgias; Trigeminal autonomic reflex; Trigemino-vascular system.