Lipoxin B4 (LXB4) is a structurally distinct product of arachidonic acid metabolism. Lipoxin B4 reduces leukocyte infiltration and mucus secretion in the nasal mucosa and decreases mast cell and eosinophil degranulation in the upper airway. Lipoxin B4 decreases airway inflammation, mucus metaplasia and hyper- responsiveness in the lower airway. Lipoxin B4 shows mucosal protective actions and has the potential for the research of allergic inflammation in the upper and lower airways^[1].