Allergic rhinitis and asthma: more similarities than differences.

Clinical epidemiological and pathophysiological studies suggest a strong functional and immunological relationship between the nose and the bronchi. Nasal stimulation, can induce bronchoconstriction by a proposed rhinobronchial reflex and inflammatory mediators originating from the nose could be inhaled and trigger bronchial inflammation. Bronchial provocation in sensitised subjects results in nasal inflammation through systemic circulation. There is an increased prevalence of asthma in patients with rhinitis relatively to patients without nasal complaints and allergic rhinitis patients have an increased risk to develop asthma. Nasal and bronchial co-morbidity is high, 75% of asthmatics have rhinitis and 20% to 40% of rhinitic patient suffer from asthma. In the World Health Initiative on Allergic Rhinitis and its effect on Asthma (ARIA) it is quoted that asthma and rhinitis are common co-morbidities suggesting the concept of one airway one disease. The term allergy rhinobronchitis has been proposed to link the association between asthma and rhinitis. The treatment of rhinitis and sinusitis is important for management of asthma. Treatment of chronic rhinitis not only reduces nasal inflammation obstruction and discharge but also can reduce lower airway hyperesponsiveness and symptoms of asthma. Treating nasal inflammation is a key point in asthma control. These data strength the functional and allergologial link between nose and bronchi. Nasal inflammation induced by nasal challenge in patients with rhinitis has the ability to also induce bronchial changes in some asthmatic patients.