Interactions of allergic rhinitis and bronchial asthma at mucosal immunology level

Allergic rhinitis (AR) and bronchial asthma (BA) could be described as different aspects of one systemic disorder, where a mutual relationship is suggested founded on the well-known link between distinct mucosal sites in the organism. Moreover, several studies discuss the intimate association between AR and BA, including the observation that AR occurs usually as the first manifestation of the allergic respiratory (atopic) march. This review focuses on the various aspects of nose and lungs interaction during the course of the allergic disease. The dysfunction of the upper and lower airways is observed often simultaneously. It is thought that AR and BA share common pathogenic features and embryological, histological, anatomical and physiological characteristics. Furthermore, the data on the common nasal-bronchial reflex, inflammatory mechanisms, similar triggers, and genetic factors, clinical and epidemiological observations, the effect from the administered therapy, all confirm the suggested relation between AR and BA. The nasal-bronchial cross-talk rely on three different pathways: the immunological in the respiratory mucosa, the neural, and the circulatory pathway. In conclusion, AR and BA often occur simultaneously and share similar pathophysiological mechanisms. Nevertheless, the observation that the similar treatment is effective in both patients, gives hope for the management and prognosis of these patients.