Rare case of sudden onset sensorineural hearing loss in a patient diagnosed with sarcoidosis
- 1 Department of Ear, Nose and Throat, West Suffolk Hospitals NHS Trust, Bury Saint Edmunds, UK
- 2 Department of Ear, Nose and Throat, North West Anglia NHS Foundation Trust, Peterborough, UK
- 3 Department of Rheumatology, Norfolk and Norwich University Hospital, Norwich, Norfolk, UK
- Correspondence to Dr Jeremy Wong; jjcyw2@doctors.org.uk
Abstract
We report the case of a woman in her 30s who was referred to the ear, nose and throat department with sudden onset left-sided sensorineural hearing loss (SNHL), left anterior uveitis and erythematous lower limb lesions with bilateral pitting oedema. Based on her symptoms, an underlying inflammatory systemic disease was suspected. Autoantibodies were negative but an X-ray and high-resolution CT scan of the chest were suggestive of sarcoidosis, which was confirmed on endoscopic bronchial biopsy. Following treatment with a course of oral steroids, the patient’s hearing has improved but she still suffers from episodes of uveitis. While immune-mediated inner ear disorders are a recognised cause of SNHL, sarcoidosis is a very rare cause. This case demonstrates the importance of screening for systemic autoimmune aetiology in SNHL and highlights the importance of an effective multidisciplinary team in the diagnosis and management of these patients.
Background
Sudden onset sensorineural hearing loss (SNHL) is commonly defined as a loss of 30 dB at three consecutive intervals and is estimated to have an incidence of 5–30 cases per 100 000 per year in the UK.1 It commonly presents unilaterally2 with associated tinnitus and occasionally vertigo.3 Despite the variety of different aetiologies that have been linked to SNHL, a definitive cause is only found in 10% of patients.4 Early treatment with steroids is crucial in hearing loss prevention in SNHL.1
Sarcoidosis is a rare systemic disease of unknown aetiology, with a global prevalence of 4.7–64 cases per 100 000.5 Commonly, sarcoidosis affects the lungs and skin, with neurological involvement only occurring in 3%–5% of cases5 of which, hearing loss is rarely reported.6 7
Collaboration between ear, nose and throat (ENT), rheumatology, respiratory and ophthalmology teams was essential in the successful diagnosis and management of this patient’s multisystem sarcoidosis. Our case thus highlights the importance of an effective multidisciplinary team (MDT) working.
Case presentation
The patient, otherwise fit and well, presented with an 11-day history of sudden onset left-sided hearing loss. This was associated with tinnitus, disequilibrium without vertigo, a week’s history of left-sided blurred vision and a 6-week history of bilateral lower leg pitting oedema with raised erythematous marks on her shins. The rash had been reviewed by her General Practitioner, who informed her that it was likely secondary to the warm weather, but arranged further follow-up.
She was initially seen by ophthalmology due to her visual symptoms, who diagnosed left anterior uveitis and telephoned the ENT team on the same day due to concerns about her hearing loss.
On review, there were no other symptoms suggestive of a connective tissue disease (CTD), with no history of constitutional symptoms (fevers, night sweats or unintentional weight loss), Raynaud’s phenomenon, sicca symptoms, mouth ulcers, photosensitive rash, serositis, salivary gland swelling suggestive of Sjögren’s syndrome or any muscle weakness. She had no history of joint swelling suggestive of synovitis, or any recent genitourinary or gastrointestinal symptoms. Aside from her history of SNHL and uveitis, there were no other features suggestive of a primary systemic vasculitis. There was no family history of autoimmunity other than the patient’s grandmother who had rheumatoid arthritis.
Otoscopy was normal, her facial nerve function was intact bilaterally and Romberg’s test was normal. Weber’s test lateralised to the right and during Unteberger’s test the patient rotated 90° to the left, suggesting left-sided audiovestibular pathology. Tympanometry was normal bilaterally, and pure tone audiometry (PTA) suggested a left-sided hearing loss (figure 1). Together with the clinical examination, the patient was diagnosed with SNHL.
Patient’s initial audiogram. HTL, Hearing Threshold Level; BC, Bone Conduction.
Bilateral lower leg pitting oedema was also noted, with 1–2 cm mild erythematous lesions that were non-tender and not raised. The patient’s photos of this lesion were reviewed by a consultant rheumatologist, who felt that these were suspicious for erythema nodosum. Coupled with her history of uveitis, the rheumatology team advised obtaining an X-ray of the chest (CXR) and blood tests, including autoantibodies, due to the possibility of a CTD or primary systemic vasculitis.
Full blood count, urea and electrolytes, renal function and liver function test results were normal. Inflammatory markers were normal, with a C reactive protein of 3 mg/L and an erythrocyte sedimentation rate of 9 mm/hour. She was negative for antinuclear antibodies, antineutrophil cytoplasmic antibodies, rheumatoid factor and anticyclic citrullinated peptide antibodies, with normal complement C3 and C4 levels. Serum angiotensin-converting enzyme was also normal at 58 U/L. The urine sediment was inactive.
MRI of the head and internal acoustic meati did not demonstrate intracranial pathology, including a cerebellar pontine angle tumour. The CXR revealed bilateral hilar lymphadenopathy raising the possibility of sarcoidosis. A subsequent high-resolution CT (HRCT) scan of the chest demonstrated enlarged mediastinal and hilar lymph nodes, with small amounts of ground glass opacities and perifissural nodularity.
Due to the limited involvement of the lung parenchyma on the CT, the respiratory MDT recommended that an endobronchial ultrasound (EBUS)-guided fine needle aspiration of the patient’s mediastinal lymph nodes would be sufficient to yield a diagnosis. As treatment could not be delayed to avoid permanent hearing loss, the EBUS was undertaken 4 months after commencement of prednisolone to allow time to reduce the dose prior to biopsy, considering the initial dose was 60 mg.
At the time of biopsy, the prednisolone dose had been reduced to 4 mg with careful monitoring from ENT. Persistence of mediastinal adenopathy despite high-dose steroids was confirmed by a repeat CT of the chest prior to EBUS. The histology demonstrated non-caseating granulomas formed of epithelioid histiocytes, with negative stains and final cultures for mycobacteria and fungi. This was consistent with a diagnosis of sarcoidosis.
After the initial review by ENT, the patient was started on a 7-day course of 60 mg of prednisolone, with a planned reduction of 10 mg every 5 days thereafter. Initially the patient improved, reporting a resolution of uveitis, disequilibrium, pedal oedema and lower limb rash. A repeat PTA performed 10 days after her initial presentation demonstrated an improvement in hearing thresholds by 10 dB. The dose was reduced from 30 to 10 mg, with a further reduction to 7.5 mg resulting in recurrence of visual symptoms. As a result, the dose of prednisolone was increased to 10 mg for 1 month.
Following this increase, the patient was re-reviewed and reported no subjective improvement in hearing. A repeat PTA performed at this time revealed a slight deterioration bilaterally in hearing at the higher and lower frequencies (figure 2).
Repeat audiogram demonstrating the mild deterioration of hearing at high and low frequencies compared with previous audiogram. HTL, Hearing Threshold Level; BC, Bone Conduction; BCL, Bone Conduction Level.
Based on these findings and the need to reduce the patient’s steroids prior to her EBUS, the prednisolone was reduced at a rate of 1 mg per week from 10 to 5 mg. Repeat PTAs were performed 21 and 49 days following the start of this tapering, which demonstrated improved hearing and thus intratympanic steroids were not considered. Unfortunately, the patient developed right anterior uveitis, which was treated successfully with topical steroid and mydriatic drops.
Following EBUS, the dose of steroids was gradually withdrawn over 4 months. Hearing improved greatly on serial PTAs performed 1, 2 and 4 months after EBUS, with most recent PTA demonstrating nearly normalised hearing (figure 3). Lung function tests performed 8 months after the onset of symptoms were normal, with spirometry demonstrating supranormal lung volumes and the diffusing capacity for carbon monoxide being 112% predicted. A CXR performed 1 year after her initial presentation was grossly normal with no hilar lymphadenopathy visible.
Recent audiogram demonstrating improvement of hearing. HTL, Hearing Threshold Level; BCL, Bone Conduction Level.
As of the time of writing, the patient remains on topical steroid eye drops due to another flare of uveitis when the oral steroids were withdrawn. Due to her repeated episodes of uveitis, she is currently being considered for mycophenolate mofentil and remains under the evaluation of the ophthalmology and rheumatology teams for this.
Investigations
Differential diagnosis
In summary, this patient presented with sudden onset SNHL, anterior uveitis and a preceding skin lesion suspicious for erythema nodosum. Coupled with a normal otoscopy and ear examination, these signs and symptoms were suggestive of a systemic inflammatory disease causing the patient’s hearing loss.
A wide variety of systemic diseases have been reported to cause audiovestibular symptoms, such as systemic lupus erythematosus and granulomatosis with polyangiitis.1 8 In this patient, the normal blood tests and the lack of characteristic features associated with these conditions ruled these out as potential causes.
With the symptom of visual disturbance, the possibility of rarer causes such as Cogan’s syndrome was considered. However, the involvement of the lungs and skin strongly suggested sarcoidosis as a potential unifying diagnosis for her constellation of symptoms.
Discussion
Involvement of the nervous system and the presentation of SNHL in sarcoidosis is rare, with only 50 reported cases found in a literature review performed in 2006.6 9 From these, the hearing loss associated with sarcoidosis is usually sudden onset SNHL, with associated vestibular features such as disequilibrium or vertigo. In 75% of these cases, the hearing loss is bilateral6 in contrast to the unilateral pattern to the hearing loss in this case.
The pathophysiology of hearing loss associated with sarcoidosis remains under debate. Sarcoidosis is characterised by the formation of non-caseating granulomas, the cause of which is unclear.5 An exaggerated immune response to pathogen-associated molecular patterns generated from killed or partially killed Mycobacteria and Propionbacteria have been proposed as aetiologic mechanisms of sarcoidosis.5 9 Within the nervous system, symptoms are generated from the formation of these granulomas, which can occur anywhere throughout the nervous system.9 This can result in protean neurological symptoms, making the diagnosis of neurosarcoidosis difficult.
In sarcoidosis-related SNHL, the formation of retrocochlear granulomas along the vestibulocochlear nerve is thought to be the cause in most cases.6 An autopsy carried out in a patient who died of neurosarcoidosis after presenting with progressive hearing and visual loss revealed widespread sarcoid neuropathy affecting both the facial and vestibulocochlear nerves in the internal acoustic meati.10 These findings match the radiological data in case reports, which demonstrate enhancing lesions in retrocochlear locations such as the internal acoustic meati or cerebellopontine angles, but no lesions within the labyrinth.6
No pathology was seen on our patient’s MRI of the head, which is consistent with the literature stating that a normal MRI of the head does not exclude neurosarcoidosis.11 In a review of case reports with MRI scans included, 2/6 did not show pathology on MRI,6 while in a review of 305 cases of neurosarcoidosis only 30% of MRI scans demonstrated cranial nerve enhancement.12 This may be because of the timing of the MRI in relation to treatment or due to the degree of inflammation.
The first-line treatment for the initial presentation of sarcoidosis and idiopathic SNHL is a short course of high-dose oral steroids5 given within 1–2 weeks of the onset of hearing loss.1 13 For second attacks or prolonged cases of SNHL, steroid-sparing immunosuppressive agents can be tried. The effectiveness of these is unclear as they have only been studied in cases of progressive hearing loss.1
Conclusion
This report details a rare case of unilateral SNHL associated with sarcoidosis. Compared with the literature, the unilateral distribution of the hearing loss is particularly unusual. The patient’s diagnosis was made thanks to close communication between ophthalmology, ENT and rheumatology teams all on the same day of initial presentation. As such, there was minimal delay in diagnosis and treatment, with the CXR being booked on the same day. The CXR was the key initial investigation given the presence of the bilateral hilar adenopathy, as the autoantibody screen was normal. The systemic nature of our patient’s presentation and this disease highlights the importance of an MDT approach in the management of these patients.
Rheumatology perspective
SNHL is an extremely uncommon extrapulmonary manifestation of sarcoidosis. Nevertheless, the clinical presentation of a relatively acute onset of anterior uveitis, erythema nodosum and bilateral leg oedema led us to consider sarcoidosis as a differential.14 The presence of bilateral hilar lymphadenopathy on CXR and high-resolution CT of the chest increased our suspicion of sarcoidosis; however, given the atypical feature of unilateral SNHL, we recommended a biopsy in order to prove our hypothesis. In addition, the disparate organ systems involved raised the possibility of an autoimmune systemic inflammatory process, such as a CTD or primary systemic vasculitis, hence our recommendation to check our patient for autoantibodies and request a urinary protein: creatinine ratio. We were supportive of early treatment with corticosteroids in this case given the significant risk of permanent hearing loss and the potential impact on the patient’s quality of life.
Learning Points
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Sarcoidosis is a rare cause of unilateral sudden onset SNHL. A timely diagnosis is important, as early steroids can prevent hearing loss with a potentially life-changing effect.
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Consideration of systemic and autoimmune inflammatory causes in the differential diagnosis of sudden onset sensorineural hearing loss is important when a patient presents with several seemingly unconnected symptoms.
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A normal autoimmune blood screen does not always rule out autoimmune disease.
Ethics statements
Patient consent for publication
Footnotes
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Contributors JW and LL conceived the case report. JW researched, designed and wrote the manuscript for the case report with LL, MC-X and LT supervising and providing guidance. MC-X further contributed by writing the rheumatology perspective on the case.
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Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
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Case reports provide a valuable learning resource for the scientific community and can indicate areas of interest for future research. They should not be used in isolation to guide treatment choices or public health policy.
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Competing interests None declared.
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Provenance and peer review Not commissioned; externally peer reviewed.
- © BMJ Publishing Group Limited 2022. No commercial re-use. See rights and permissions. Published by BMJ.
References
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