Abstract
Dear Sir I read with great interest the recent paper by Boulton et al. concerning ‘red ear syndrome’ (1). The authors seem to suggest this syndrome is a rare presentation according to existing literature citations. Subsequent to reading the paper, I conducted an informal census of presenting patients in our facial pain clinic over a 2-week period and found that approximately one of three patients reported red ears as a primary complaint or associated symptom. We have also randomly reviewed existing charts and found the results consistent with that of our informal patient survey. This syndrome often presents in our patients complaining of temporomandibular dysfunction and/or cervical spine pain. The authors, in fact, report that one case studied appeared subsequent to a prolonged dental procedure in which the mouth was open for 4 h.
As mentioned by the authors, the aetiology of red ear syndrome remains unclear at present. Innervations of the helix and antihelix of the ear consist of the auriculotemporal nerve, the greater auricular nerve and the lesser occipital nerve (2). The concomitant presentation of red ear with temporomandibular disorders may suggest a causal link with trigeminal nociceptive conditions. The convergence of the upper cervical nerve roots with the trigeminal nucleus caudalis could also support the notion of increased trigeminal nerve activity in this syndrome (3). It could be postulated that a chronic nociceptive condition involving the trigeminovascular system alters and/or hinders the sympathetic activity, allowing for increased or uncontrolled activity of the parasympathetic system, similar to that seen in migraine and other autonomic cephalgias (4). Ramirez and Kirsner have presented a case of erythromelalgia involving the ears (5), with presenting symptoms similar to those discussed by Boulton et al., but whether or not these are related conditions remains unclear.
Most patients seen in our facial pain centre have experienced their painful condition for at least 6 months prior to presentation, creating a centralized pattern to their chief complaint. We often notice many concomitant painful mechanisms that can potentially be traced back to a single entity such as nocturnal bruxism. In many cases, treatment of the sleep movement disorder (bruxism) via nocturnal parafunctional control (bite splint therapy) has proven to be successful at not only eliminating the primary pain complaint but also the concomitant conditions, such as red ear syndrome, by decreasing and, in some cases, eliminating the trigeminal nerve hyperactivity. In those cases that present with concomitant cervical complaints, local anaesthetic combined with a corticosteroid solution, infiltrated at the lesser occipital nerve near the mastoid notch (6), has proven to be therapeutic on an immediate as well as, in some cases, a long-term basis. With both therapeutic modalities, the goal is to decrease trigeminal nerve nociceptive signalling. This targeted therapy seems also to result in a correction of autonomic dysfunction, similar to that seen when an occipital nerve block is administered for autonomic cephalalgias such as cluster headache (7).
Although the therapies employed in our centre seem to treat red ear syndrome successfully, many questions remain as to its aetiology. I applaud the work of the listed authors as well as of others who have presented papers on this subject. I especially want to thank Dr Dodick for his encouragement. I would speculate that the lack of published material on the subject has more to do with a lack of questioning the patient with regard to this specific entity as an associated symptom rather than it being a rarity in the facial pain patient population. Perhaps if patient questionnaires in secondary and tertiary pain centres listed the entity as a standard question, more cases would be available for investigation and discussion.