A case of acute labyrinthitis due to intra-aural tick infestation: a case report

Abstract

Background

Intra-aural tick infestations, though uncommon, pose a serious clinical challenge owing to the risk of acute labyrinthitis—an inflammatory condition of the inner ear. This inflammation can lead to severe complications such as sensorineural hearing loss, vertigo, and facial nerve palsy. Prompt recognition and management are crucial to prevent these adverse outcomes.

Case presentation

A 21-year-old female patient of Limbu ethnicity from Dharan presented with sudden-onset right-sided otalgia, accompanied by vertigo, emesis, and auditory impairment. Otoscopic examination revealed a tick lodged in the anteroinferior aspect of the external auditory canal, and audiological assessment indicated profound sensorineural hearing loss on the affected side. Treatment involved careful tick removal using suction and forceps, supplemented by pharmacotherapy including antiinflammatory agents, analgesics, systemic steroids, and prophylactic antibiotics. Her symptoms resolved completely within 4 weeks, with postinterventional audiometry confirming restored auditory acuity.

Conclusion

This case underscores the importance of prompt clinical assessment and treatment in cases of aural tick infestation. The successful use of a multimodal approach highlights the effectiveness of comprehensive management. Further research is warranted to optimize treatment strategies and improve outcomes in similar cases.

Background

The realm of otorhinolaryngology frequently involves managing cases where foreign bodies, whether living or nonliving, demand careful attention and specialized intervention. Tick infestations in the external auditory canal (EAC) are infrequent, presenting in less than 1% of patients with ear complaints [1]. Despite their rarity, this condition can lead to notable complications such as labyrinthitis-induced tinnitus, hearing loss, vertigo, or facial paralysis (palsy) [1]. We report one such rare case of intra-aural tick infestation presenting with labyrinthitis.

Case presentation

A 21-year-old female patient of Limbu ethnicity from Dharan, without known comorbidities, sought consultation at the otorhinolaryngology outpatient department with a 1-week history of sudden and progressively worsening pain in her right ear. The pain, described as piercing, was partially relieved with oral analgesics; 2 days before the presentation, she experienced an exacerbation of symptoms, including dizziness intensified by head movement, accompanied by nausea and vomiting. Additionally, she reported decreased hearing in the right ear, coupled with tinnitus. There was no preceding history of upper respiratory tract infection, ear discharge, or instrumentation in the ear.

The patient demonstrated good orientation to time, place, and person, along with stable vital signs. On examination using a 512 Hz tuning fork, the Rinne test revealed normal findings in the left ear (air conduction > bone conduction), while the right ear showed no response, suggesting profound sensorineural hearing loss. The Weber test lateralized to the left ear, further confirming severe-to-profound sensorineural hearing loss in the right ear. The left ear showed no abnormalities. Otoscopy revealed a congested external auditory canal (EAC) and the presence of a foreign body in the anteroinferior bony wall (Fig. 1). Further examination using otoendoscopy uncovered a tick lodged in the canal wall skin, surrounded by minimal ecchymosis and edematous skin. Notably, no live ticks were found. The tympanic membrane was intact, and grade 1 left-beating nystagmus was also observed.

Fig. 1

Otoscopy revealing a congested external auditory canal (EAC) and the presence of a foreign body (tick) in the anteroinferior bony wall

The pure tone audiometer revealed severe-to-profound right sensorineural hearing loss (Fig. 2). Using suction and Hartmann’s forceps, the tick was delicately dislodged and removed. Subsequent examination of the canal wall followed. The patient was initiated on a comprehensive treatment regimen to ensure optimal recovery. For antiinflammatory purposes, she was prescribed ibuprofen 400 mg orally every 6–8 hours as needed for 7 days. To manage pain, she received paracetamol 500 mg orally every 4–6 hours as needed for the same duration. Additionally, prednisolone 20 mg orally once daily was administered, with the dosage tapering over a period of 14 days, to address inflammation and prevent further complications. As a precautionary measure against potential infections, amoxicillin–clavulanate 500/125 mg orally every 8 hours was prescribed for 7 days.

Fig. 2

Right ear pure tone audiometry on presentation showing severe-to-profound sensorineural hearing loss

At the 1-month follow-up, the patient reported complete resolution of otalgia, with no further complaints. Otoscopy revealed a clear right external auditory canal with an intact tympanic membrane. Pure tone audiometry demonstrated a reversal of the previously documented hearing loss, and follow-up tuning fork tests confirmed the resolution of symptoms in the right ear (Fig. 3). The positive outcome highlights the effectiveness of the intervention and the patient’s improved auditory health.

Fig. 3

Right ear pure tone audiometry 1 month after treatment

Discussion and conclusion

Tick-borne diseases, classified within the realm of vector-borne illnesses, pose a significant threat to both livestock and human populations. In cases where ticks invade the external auditory canal (EAC), the primary concern arises as acute ear pain, triggered by an enzyme in tick saliva that initiates pronounced local inflammation [2]. Furthermore, the attachment of ticks to the eardrum introduces the potential complication of tinnitus. The identified culprit behind vertigo and tinnitus in our case was acute labyrinthitis, discerned from the duration of symptoms extending over 1 week. The convergence of symptom onset, the presence of a dislodged tick, and persistent otalgia collectively indicated acute labyrinthitis originating from a toxin resulting from an aural tick bite—a distinction from vestibular neuronitis, a condition typically sparing auditory function, unlike the hearing impairment observed in this specific patient. Labyrinthitis may arise from a microperforation of the tympanic membrane due to the tick bite. The authors hypothesized that this perforation provided access for the neurotoxin-containing tick saliva to enter the middle ear, initiating inflammation. Although the membrane appeared intact during examination, a small perforation could have previously allowed the neurotoxins to enter the inner ear, causing labyrinthitis symptoms. By the time of evaluation, this perforation may have healed, explaining the absence of visible damage, while still accounting for the labyrinthitis symptoms [3]. Although Borrelia burgdorferi-induced Lyme disease may occasionally affect balance and hearing indirectly, Lyme-related vestibular symptoms are usually part of a larger systemic picture. This broader presentation often includes joint inflammation, fatigue, and cognitive impairments, which distinguishes it from the localized symptoms seen in tick-induced labyrinthitis [4].

While aural tick infestation may not require an emergency designation, the significance of its management is underscored by the presence of associated pain, inflammation, and local irritation [1]. Exploring the research landscape, as demonstrated by the work of Indhudaran et al., draws attention to the multifaceted complications of tick infestation, spanning from ear bleeding and vertigo to facial nerve weakness in conjunction with otitis media [5]. Beyond this, ticks release neurotoxins inhibiting acetylcholine, potentially inducing respiratory distress or paralysis. In severe cases, the tick’s mouthparts attaching to the tympanic membrane can lead to perforations and the release of enzymes into the middle ear [6, 7]. These intricacies underscore the imperative need for prompt and comprehensive management of aural tick infestations. Regular follow-ups become indispensable owing to the looming risk of perforation. The judicious determination of whether a tick’s mouthparts are attached before removal becomes a crucial decision, steering clear of triggering foreign body granuloma development [8].

The primary approach to managing intra-aural tick infestation revolves around the meticulous extraction of all tick parts using forceps, occasionally requiring anesthesia for more intricate cases. Patient recovery, often spanning 4 weeks post-tick removal [4], resonates with our case, where symptoms gracefully resolved within a month. Meanwhile, the use of short-course systemic steroids, with or without antibiotics, introduces an experimental layer to the discourse—insufficient data stand as a barrier to a definitive recommendation or dismissal of their added benefits [9]. This holds true unless a confirmed infectious process, such as otitis externa, otitis media, or tick-borne diseases, is in play [9, 10]. Moreover, some studies suggest the use of quantitative polymerase chain reaction (qPCR) to detect rickettsial infections in cases of intra-aural tick infestations, especially when facial nerve palsy is observed, indicating a possible rickettsial etiology. This adds an important diagnostic layer to the management, ensuring that any underlying infections are appropriately identified and treated [11]. The treatment approach aims to mitigate the inflammatory response and address any potential bacterial infection, although more data are needed to definitively support the routine use of steroids [11, 12]. Given the complexity of such cases, interdisciplinary collaboration between otolaryngologists, infectious disease specialists, and neurologists is often beneficial to ensure comprehensive care and favorable outcomes for patients with intra-aural tick infestations.

This case underscores the critical importance of early diagnosis and intervention in intra-aural tick infestations to prevent severe complications such as acute labyrinthitis. The successful management of the patient’s condition, evidenced by complete symptom resolution and restored hearing, highlights the effectiveness of careful tick removal. Clinicians must maintain a high index of suspicion for tick infestations in patients presenting with acute otalgia, vertigo, and sensorineural hearing loss, ensuring prompt otoscopic examination and appropriate therapeutic measures.