Case Presentation: A 56-year-old male presented to the emergency department for longstanding and persistently worsening headaches, subjective fevers, chills, malaise, and significant weight loss. One month prior to this visit, he had a dental abscess that was successfully treated with a course of Augmentin; since that time his headaches, chills, malaise, and significant weight loss worsened. He had no other past medical history. In the emergency department, his vital signs were normal. On physical exam, he appeared uncomfortable and frail. Lymphadenopathy was present in his left submandibular, left supraclavicular, and left axillary regions. On laboratory investigations, CBC was normal, CMP was normal, and CRP elevated to 7.8 mg/dL with repeat serial testing increasing to 11.6 mg/dL. Further serological work-up included a positive ANCA, C-ANCA titer of 1:40, elevated proteinase 3 AB at 46.6 AI, negative MPO antibody test, negative GBM antibody test, negative histoplasmosis test, negative HIV test, negative cryptococcal test, and negative Blastomyces test. Two blood cultures were negative. A urinalysis performed was also unremarkable. Brain MRI was negative for any brain abscess though it did reveal acute sinusitis. Chest x-ray revealed bilateral consolidative airspace opacities. CT chest revealed multiple pulmonary nodular lesions with cavitations. CT-guided biopsy of these lesions were negative for malignancy, tuberculosis and fungal infections, but showed mass-like necrotizing inflammatory process suggestive of GPA. A bronchoscopy on two separate occasions revealed chronic bronchitis with chronic granulomatosis and inflammation. Our patient was diagnosed with GPA. He was empirically started on intravenous ampicillin/sulbactam, prednisone, methotrexate, and folic acid. He clinically improved and was discharged home on amoxicillin/clavulanic acid for ten days for his consolidative lung lesions.
Discussion: GPA is a rare necrotizing vasculitis that affects small to medium-sized blood vessels. The clinical presentation is classically a triad of necrotizing granulomas in the upper airways, the lungs, and necrotizing glomerulonephritis which can lead to renal failure. GPA can be further classified as “classical” which involves the lung (95% of cases), upper respiratory tract/sinuses (75%-90% of cases), and kidneys (80% of cases). Limited GPA involves mainly the respiratory tract. Our patient presented with constitutional symptoms, sinusitis (upper respiratory tract), and necrotizing granulomas in the lungs, with limited renal involvement. Our patient did have microscopic hematuria with no red blood cell casts, no proteinuria, and no reduced renal function. Our patient did have “limited” disease, as there was only limited renal involvement. Approximately 50% of these patients have kidney disease at clinical presentation, characterized by reduced renal function, proteinuria, and hematuria. Providers must be aware of the classic and limited presentations of GPA, as they may go misdiagnosed because of the atypical presentation. Awareness of limited GPA can increase the likelihood of early recognition and appropriate treatment.
Conclusions: There is an increased likelihood of misdiagnosis for limited granulomatosis with polyangiitis because of its atypical presentation. Awareness of atypical or “limited GPA” can increase the likelihood of early recognition, early diagnosis, and appropriate treatment with immunosuppressive drugs, which are crucial for a favorable outcome.