Mechanisms of rhinitis

Mast cell degranulation leads to the release of histamine and a host of oth er mediators. However, histamine remains preeminent in proffering the vexat ious symptoms of allergic rhinitis including itching, sneezing, dripping, a nd congestion. The mechanisms of symptom production in rhinitis will be rev iew ed with an eye toward effects on mucosal resident cells such as epithel ium, endothelium, and glands, the role of nociceptive and parasympathetic n erves, and the recruitment and activation of leukocytes in the mucosa. The benefits and mechanisms of action of antihistamines, anticholinergic agents , and glucocorticoids will be discussed.