| Microscopic polyangiitis is a small-vessel
necrotizing vasculitis associated with anti-neutrophil cytoplasmic
antibodies and presents itself with glomerulonephritis
and hemorrhagic pulmonary capillaritis. Peripheral
nervous system involvement is common in anti-neutrophil
cytoplasmic antibodies-associated vasculitis, but brachial
plexopathy is unusual. We present the case of a 22-year-old
man with known microscopic polyangiitis who was under
maintenance therapy with prednisolone and cyclophosphamide
and developed cough, dyspnea, and hemoptysis which
increased in 6 days accompanying pain and paresthesia in
the upper limbs. His physical examination revealed hypoesthesia,
absence of deep tendon reflexes, and decreased
muscle strength in the upper limbs. His chest computed
tomography scan showed ground glass pattern in the lower
and middle lobes. Electromyography and nerve conduction
study showed bilateral brachial plexopathy with involvement
of all of the cervical roots that were more severe in
the lower roots and left side. |