Granulomatosis with Polyangiitis following COVID-19 in an Adolescent.

Granulomatosis with polyangiitis (GPA) is a systemic disease that causes vasculitis in various organs. Although the mechanism of pathogenesis remains unclear, infection has been reported to be a causative factor. We herein report a case of GPA that developed following coronavirus disease 2019 (COVID-19) in an adolescent girl. One month after contracting mild COVID-19, the patient had facial allodynia, a fever, and weight loss and was admitted for multiple nodular shadows on a chest roentgenogram. GPA was diagnosed based on pathological findings of the lung and nasal mucosal biopsies. She received methylprednisolone and rituximab, and her symptoms and radiological findings improved.