Allergic rhinitis and asthma

Allergic rhinitis and asthma are frequently associated diseases, as demonstrated by epidemiologic data. Allergic rhinitis patients without symptomatic asthma often show unspecific bronchial hyperresponsiveness, which is considered an intermediate stage in asthma development. Therapy of allergic rhinitis with intranasal glucocorticoids or with antihistamines can diminish asthmatic symptoms and bronchial hyperresponsiveness. First available data suggest that immunotherapy of allergic rhinitis is able to prevent the development of asthma. The pathophysiology of the link between allergic rhinitis and asthma is not yet clarified. Expansion of the nasal inflammatory process by systemic distribution of mediators and recruitment of inflammatory cells represents a plausible hypothesis.