Microbial influences on chronic rhinosinusitis.

The nasal microbiome is altered in chronic rhinosinusitis (CRS), characterized by increased bacteria density and higher relative abundance of Staphylococcus aureus compared to healthy adults. This review examines determinants of S aureus nasal colonization, focusing on immune control and its evasion by the bacteria. CRS and asthma share pathomechanisms of chronic airway inflammation and often co-occur. In both conditions, many patients are sensitized to secreted factors of S aureus enterotoxins and serine protease-like proteins, and produce specific IgE, which influences the disease course. Therefore, we propose to incorporate S aureus-specific IgE measurements into the routine diagnostic evaluation of CRS and asthma.