And they release these tiny allergens we call antigens that flow via these epithelial cells and in two our plasma cells. And the plasma cells see these antigens as pathogenic and begin producing the corresponding complementary immunoglobulin er antibodies. Now, these antibodies then bind onto our mast cells, onto these special receptors. And now these antigens can go on and bind onto these antibodies at the variable portion. And when the binding takes place these release histamine and other chemicals that basically dilate the blood vessels and that brings more blood to that area, causing redness. It also increases the leakiness, the leakiness of our capillaries which can lead to edema the process of swelling.