Acute pneumonitis or vasculitis? A severe case with multiple organ involvement

This report describes a case of a 37-year-old man affected by weakness, cough, fever and arthralgia for three months and a single episode of arthritis affecting the left ankle. The symptoms worsened and he was admitted to our hospital. First level blood tests showed an increase in inflammatory proteins, leukocytosis with eosinophilia, positive anti-neutrophil cytoplasm antibody (ANCA) and PR-3 ANCA antibodies, initial renal failure with elevation of creatinine and microscopic hematuria and initial proteinuria in the urine tests. As the chest x-ray revealed a perihilar pneumonitis with a well-defined margin area in the right lung, we started antibiotic therapy. The lung was studied with high-resolution chest computed tomography, which showed interstitial lung disease with more consolidative areas, some of which had a reverse halo sign. As clinical and laboratory data suggested a multiple organ involvement, second level tests were performed to look for the presence of systemic vasculitis.