Toe Necrosis: A Surprising Herald of Antineutrophil Cytoplasmic Antibody-Associated Vasculitis.

Systemic vasculitides can affect any type of blood vessel and can present with various signs and symptoms depending on the site and type of affected blood vessels. The antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) can affect small- to medium-sized vessels. It can involve various organs and present with varying clinical and pathological features. Although rare, it can affect the blood vessels of the toes, leading to distal ischemia and gangrene. A 74-year-old woman with multiple comorbidities presented with symptoms of chronic nasal congestion, joint pain, and neuropathy, prompting autoimmune evaluation. Due to positive antinuclear antibody and perinuclear ANCA titer, initial treatment with low-dose prednisone and methotrexate was introduced. However, later during the course, she developed bilateral toe necrosis despite being on treatment. The workup for neurological and cardiovascular causes for the toe necrosis was negative. The patient ultimately required bilateral metatarsal amputation. Post-surgery, she was treated with rituximab and prednisone, which resulted in improvement in vasculitis. This case highlights the importance of recognizing rare presentations of AAV to enable timely intervention and prevent severe complications.