Histamine and leukotrienes in allergic rhinitis

play an important role in nasal congestion, secretion and infiltration. Thus inhibition of leukotriene synthesis and action seems to be promising in the therapy of allergic rhinitis, especially regarding nasal congestion. Azelastine and mizolastine, two second gener ation histamine H-1-antagonists possess anti-inflammatory leukotriene-antagonistic properties. Their efficacy in the treatment of nasal obstruction has been proven in various studies.Our knowledge about the pathophysiology,oy of allergic rhinitis has been enriched in recent years by the investigation of different mediators (e.g. cytokines), involved cells like mast cells or eosinophils, and mechanisms like the adhesion cascade. This has led to the realization that allergic rhinitis is a persistent inflammation. While histamine is still considered the most important mediator of early phase reaction and mainly responsible for the symptoms sneezing, itching and rhinorrhea, other mediators like leukotrienes became matters of further scientific interest. Leukotrienes play an important role in nasal congestion, secretion and infiltration. Thus inhibition of leukotriene synthesis and action seems to be promising in the therapy of allergic rhinitis, especially regarding nasal congestion. Azelastine and mizolastine, two second generation histamine H-1-antagonists possess anti- inflammatory leukotriene-antagonistic properties. Their efficacy in the treatment of nasal obstruction has been proven in various studies.