Granulomatosis With Polyangiitis Presenting As Orbital Apex Syndrome.

Granulomatosis with polyangiitis (GPA) is a rare small-vessel vasculitis that typically presents with a triad of sinonasal, pulmonary, and renal symptoms. Here, we present the case of a 43-year-old female with a history of substance use disorder who presented with vision changes and worsening left eye pain over five days. Previous evaluations raised concerns about GPA versus cocaine-induced vasculitis, but diagnostic confirmation was hindered by a lack of medical follow-up. Prompt multidisciplinary intervention led to significant improvement following steroid therapy and IV antibiotics, and the patient was ultimately diagnosed with a high GPA. This case highlights the complexities involved in diagnosing and managing GPA presenting as orbital apex syndrome, particularly in patients with comorbidities and non-adherence to medical follow-up.