Microscopic polyangiitis most commonly manifests as perinuclear anti-neutrophil cytoplasmic antibodies (p-ANCA) positive necrotizing glomerulonephritis or pulmonary capillaritis and presents with non-specific symptoms [16]. The presence of upper airway involvement and positive anti-PR3 antibody in this patient makes the diagnosis of MPA unlikely. This evidence concerns the gene PRTN3 and microscopic polyangiitis.