Facial nerve paresis in the course of masked mastoiditis as a revelator of GPA

Purpose The aim of this study was to present a series of 6 patients with facial nerve palsy and masked mastoiditis which constituted as revelators of localized granulomatosis with polyangiitis (GPA) and to evaluate the utility of the ACR/EULAR 2017 provisional classification criteria for GPA in such cases. Methods Study group included 58 patients with GPA. Cases with facial nerve palsy and masked mastoiditis were thoroughly analyzed. Results The mean age of patients was 37 years. All manifested unilateral facial nerve palsy and hearing loss, while only 2 reported aural complaints suggesting inflammatory cause of the disease. All cases were qualified for surgical intervention. Intraoperative findings were similar: granulation tissue in tympanic cavity and/or pneumatic spaces of the mastoid process. Only 50% of histopathological results suggested vasculitis. In all cases, elevated levels of antineutrophil cytoplasmic antibodies (ANCA) against peroxidase 3 (PR3-ANCA) were determined. Two patients presented rapid progression of the disease and died within 1 week and 2 months, respectively. Four other patients manifested gradual improvement of hearing and facial nerve function after treatment. Conclusion GPA should be included into differential diagnosis in all cases of persistent facial nerve palsy especially when otological symptoms coexist. Even localized GPA could be very aggressive, revelating generalized form of the disease. Rapid systemic treatment of GPA can protect hearing and facial nerve from permanent severe dysfunction. The ACR/EULAR 2017 provisional classification criteria for GPA seem to be valuable tool in diagnosing ENT patients with localized otological form of the disease.