Otologic Manifestations of Immunoglobulin G4-Related Disease

The IgG4-related disease (IgG4-RD) is a systemic autoimmune condition that can affect any organ. Few studies, however, describe otologic symptoms as initial manifestations. We present a case of IgG4-RD in a patient with progressive sensorineural hearing loss (SNHL), serous otitis media (SOM), dizziness, and dural thickening.

A 53-year-old female presented with 1 year of progressive right hearing loss refractory to high-dose steroid treatment, 6 months of left hearing loss, dizziness, and right SOM. Audiogram showed right profound SNHL and left mild-to-moderate sloping SNHL. Computed tomography of temporal bone and magnetic resonance imaging (MRI) demonstrated only nonspecific mucosal thickness in both mastoids. Electronystagmography revealed bilateral vestibular weakness, and vestibular rehabilitation did not improve the patient’s dizziness.

Upon follow-up, the patient complained of worsening left hearing and aural pressure. Audiograms showed stable hearing until after 3 months, when it progressed to left moderate-to-severe mixed hearing loss with a new 25 dB air–bone gap in most frequencies. Computed tomography then showed partially opacified left inferior mastoid air cells and a small focus of soft tissue attenuation in the left middle ear cavity at the Eustachian tube orifice. Eustachian tube dysfunction was considered, but caution was given for tympanostomy tube placement since this was the only hearing ear.

About 18 months after onset of initial symptoms, the patient experienced significant headaches, and MRI showed small, thin, left subdural fluid collection versus dural thickening. Repeated MRI 4 months later demonstrated worsened thickening and was described as enhancing meninges overlying the left cerebral hemisphere and extending across the base of the floor middle cranial fossa and into the left tentorium (Figure 1). The patient was referred to a leading ear institute for second opinion with no conclusion after thorough investigation. She then underwent left temporal craniotomy for dural biopsy and, with pathology consultation, was diagnosed with IgG4-related meningeal disease.

Figure 1.

Coronal T1 with contrast with arrows demonstrating thickened dura with enhancement.

Rheumatology and neurology consults were obtained, and the patient was given methotrexate after not tolerating initial treatment with prednisone. Magnetic resonance imaging demonstrated continued dural thickening, consistent with IgG4-RD. After receiving rituximab infusions every 6 months for 3 doses, MRI showed stable disease. The patient continues to receive infusions, and her left hearing is stable. Her disease did not affect any other organs.

IgG4-RD can result in significant morbidity, emphasizing the importance of early diagnosis and treatment. However, diagnosis can be challenging because its manifestations vary widely.

IgG4-RD involving the head and neck often presents with tumefactive lesions, and workup of organ tumefaction is part of a diagnostic algorithm proposed by Stone et al. ¹ Our patient had no obvious organ swelling but presented with otitis media with serous effusion. One previous report of IgG4-RD describes a markedly edematous and thickened middle ear and postulates that middle ear mucosa could be an IgG4-RD target. ²

Dural biopsy results were consistent with IgG4-related hypertrophic pachymeningitis (IgG4-RHP), a subset of hypertrophic pachymeningitis. ^3,4 While headache, cranial nerve palsies, and other symptoms were more frequent presentations, 9% of 33 patients demonstrated SNHL associated with IgG4-RHP in one review. ⁵ IgG4-related hypertrophic pachymeningitis-related unilateral hearing loss is suggested to result from mass effect, nerve compression, or vascular compromise. ³ However, this does not completely describe our case given left cerebral hemispheric enhancement with more severe right SNHL. Further research is needed to decipher the mechanisms of hearing loss in IgG4-RD. Also, while SNHL and SOM are both common clinical presentations, SOM associated with SNHL is unusual, and the differential diagnosis should be expanded to include IgG4-RD.

Though otologic manifestations are rare presenting features, IgG4-RD should be considered in the differential diagnosis for refractory otologic symptoms.