Severe microscopic polyangiitis with unilateral vocal cord paralysis as initial manifestation

Case Description: A 16 year-old female who presented with initial ear, nose and throat manifestations who later progressed to severe renal disease, requiring hemodialysis after 11 months of unique laryngeal involvement.
Clinical Findings: Unilateral vocal cord paralysis without other symptoms or signs, but with positive perinuclear anti-neutrophil cytoplasmic antibodies (ANCA) and anti-myeloperoxidase autoantibodies, followed an unfavorable course months later with rapidly progressive glomerulonephritis. Renal biopsy confirmed an ANCA-associated vasculitis. She was diagnosed with microscopic polyangiitis.
Treatment and Outcome: High-dose glucocorticoids, intravenous cyclophosphamide, plasma exchange and finally, hemodialysis and renal transplantation.
Clinical Relevance: In contrast to granulomatosis with polyangiitis (Wegener), ear, nose and throat manifestations in microscopic polyangiitis are uncommon, while involvement of the lungs and kidneys are usual. We present a case with an isolated rare involvement, which progressed to severe disease. This atypical case warns about laryngeal symptoms as initial manifestation of an anti-myeloperoxidase positive systemic vasculitides, and emphasizes the relevance of close observation when unexplained isolated conditions with accompanying evidence of autoimmunity, in this case high levels of specific autoantibodies, are present.

Keywords
Microscopic polyangiitis; vocal cord paralysis; larynx; myeloperoxidase; ANCA-associated vasculitis