How does Cromolyn prevent allergy symptoms?
When an allergen such as pollen enters the body, it attaches to certain antibodies on specific cells in the body called mast cells. This starts a cascade of events leading to the influx of calcium into the mast cell. The mast cell then bursts open and releases histamine, which is the mediator that causes the allergic reaction and the itchy, watery eyes and runny nose you may experience. Cromolyn (sodium cromoglycate) binds to the mast cell and indirectly blocks the entry of calcium ions, thereby preventing the release of histamine. Since Cromolyn blocks histamine release, it prevents the allergy symptoms that histamine usually causes. It has no intrinsic bronchodilator, antihistaminic or anti-inflammatory activity.