The Area to Avoid in the Ear Canal to Prevent a Cough Reflex During Ear Suction

Background and Objective: Ear suction is a commonly performed procedure for both diagnostic and therapeutic purposes in the management of ear disorders. However, some patients may experience involuntary coughing or discomfort during the procedure, which is believed to result from stimulation of the sensory nerves supplying the external auditory canal. The external auditory canal receives sensory innervation from several nerves, including the auriculotemporal nerve from the trigeminal nerve (cranial nerve V), the auricular branch of the vagus nerve, the facial nerve, the glossopharyngeal nerve, and the great auricular nerve from the cervical plexus (C2–C3). Variations in the distribution of these nerves among individuals may lead to differences in sensitivity across the external auditory canal. Stimulation at certain sites may induce a more pronounced cough reflex or immediate pain than at others. This study aimed to identify the specific anatomical areas of the external auditory canal that should be approached with caution during ear suction due to their tendency to provoke an immediate cough reflex, as well as to assess the level of pain associated with each site. The findings may help clinicians determine safer suction areas, minimize unnecessary stimulation, improve patient comfort, and enhance the overall safety of otologic procedures. Methods: This descriptive cross-sectional study was conducted among patients undergoing ear suction at the Department of Otolaryngology, Vachira Phuket Hospital, between June 1 and July 7, 2025. The objective was to evaluate the anatomical sites within the external auditory canal associated with immediate induction of the cough reflex and the corresponding pain level. Suctioning was performed in the asymptomatic ear at four sites: anterior canal wall, posterior canal wall, superior canal wall, and inferior canal wall. The order of stimulation was randomized. Cough reflex occurrence and pain intensity were recorded using the Numeric Rating Scale (NRS, 0–10), and differences in mean scores across sites were analyzed using independent t-tests. Results: Among 43 patients, 15 (34.9%) exhibited an immediate cough reflex during ear suction. The inferior wall of the external auditory canal was the most frequent trigger site (7/15 cases, 46.7%), followed by the posterior (5/15), anterior (2/15), and superior walls (1/15). The highest mean cough score (8.0 ± 1.2) was observed following inferior wall stimulation, whereas posterior wall stimulation resulted in the highest mean pain score (2.0 ± 0.8). Differences in both cough and pain scores across stimulation sites were statistically significant (p < 0.01 and p = 0.02, respectively), based on independent t-tests. Conclusion: The inferior wall of the external auditory canal appears to be the most frequent anatomical site triggering an immediate cough reflex during ear suction, possibly due to vagal innervation via Arnold’s nerve. Awareness of this sensitivity and minimizing stimulation at this site may help improve patient comfort and enhance procedural safety.