Granulomatosis With Polyangiitis Presenting as Acute Bilateral Facial Nerve Paralysis

Backgroud: Granulomatosis with polyangiitis (GPA) is a rare systemic autoimmune disease characterized by necrotizing small-vessel vasculitis, commonly involving the head and neck region, facial palsy is an uncommon head and neck presentation of GPA, and bilateral facial palsy is exceedingly rare. Objective: We present the case of a patient who presented with bilateral acute facial paralysis with final diagnosis of GPA to raise awareness of this rare presentation of GPA. Methods: retrospective chart review. Case presentation: We present a case of a 52-year-old female, who presented with right-sided facial paralysis started 6 weeks earlier and left sided facial nerve paralysis started 5 days before presentation. In addition, patient suffered from severe bilateral mixed hearing loss and otorrhea. Physical exam revealed polypoid tissue occluding the ear canal and purulent otorrhea. Computed tomography showed completely opacified mastoids bilaterally without bony erosion, and without evidence of cholesteatoma on magnetic resonance imaging. No evidence of nasal, respiratory, or renal involvement was detected. Extensive lab work was within normal limits, besides elevated C-reactive protein and positive serine-proteinase 3 (PR3). Patient underwent left mastoidectomy with facial nerve decompression. The left middle ear space and mastoid were filled with dense granulation tissue. The facial nerve was decompressed and found to be intact to nerve stimulation. Pathology report was positive to PR3, confirming the diagnosis of GPA. She was started on rituximab and prednisone, and 6 weeks after surgery, the patient had improved otalgia, as well as significant improvement in left FN function to HB II, with right FN function at HBV. Conclusion: In the existing literature, there are 14 cases of bilateral facial palsy as a presentation of GPA, however, this presentation is the first in the existing literature without evidence of systemic involvement. This highlights that the absence of other systemic involvement and negative initial autoimmune workup does not exclude GPA as the etiology of facial palsy. Continued re-evaluation of systemic involvement and biopsies of middle ear contents is crucial in diagnosis.