C1S and sinusitis: The safety results of a study evaluating the efficacy ofnanofiltered human C1-esterase inhibitor (CINRYZE, ViroPharma Inc, Exton, PA) inprophylactic therapy show the most common adverse events to be sinusitis, rash,headache, and upper respiratory infection, irrespective of causality (Table 3)[46].In the opinion of the investigators, the only adverse events that were possibly ordefinitely related to this C1-esterase inhibitor were pruritus and rash,lightheadedness, and fever[43].