Inflammatory diseases of the sinuses: an overview of immunology

We have provided an overview of the immune system and its components. These components--cell-mediated and humoral immunity, the complement system and the different phagocytic cells--all function in concert to protect the body from foreign invaders. When this powerful immune system behaves in a misdirected fashion, however, disease states develop from its injurious effects. One such disease process, intimately related to sinus disease, is allergic rhinitis, which starts as an IgE-mediated response and evolves into an extensive reaction with the contribution of several inflammatory cells and mediators (Fig. 5).