BACKGROUND There is a link between the upper and lower airways. Allergic rhinitis and bronchial asthma may coexist, but they can also affect each other. OBJECTIVE To investigate the possibility of nasal allergy being able to induce a secondary asthmatic response (AR). METHODS In 82 asthmatics responding insufficiently to standard antiasthmatic therapy and demonstrating negative ARs to bronchial challenge with allergen, 82 nasal challenges with various inhalant allergens were performed by means of rhinomanometry in combination with spirometry (vital capacity and forced expiratory volume in 1 s). In 33 control subjects suffering from allergic rhinitis (n=18) or bronchial asthma (n=15) only, 33 nasal challenges with inhalant allergens were performed by rhinomanometry and supplemented with spirometry. RESULTS Of the 82 nasal challenges, 69 produced a positive nasal response (p<0.01) and 13 were negative (p>0.05). In 58 cases with a positive nasal challenge, a secondarily induced AR was recorded (p<0.01). The following types of ARs were documented: 17 isolated immediate ARs (p<0.01), 24 isolated late ARs (p<0.01), 12 dual late ARs (immediate + late, p<0.05 and p<0.01, respectively) and 5 isolated delayed ARs (p<0.05). CONCLUSIONS (1) An allergic reaction occurring initially in the nasal mucosa can play an important role in bronchial asthma by inducing a secondary AR, and (2) nasal challenge with allergen performed by rhinomanometry in combination with lung function recording (e.g. spirometry) may then determine the possible need for additional intranasal antiallergic treatment and sparing of antiasthmatic drugs.