According to the GA2LEN recommendations, nasal challenge test with lysine-aspirin should be performed only in patients with severe asthma, because the sensitivity of this test has been lower than in bronchial and oral challenge tests. The AIA patient group often have severe asthma with impaired lung function, and therefore improvement of the nasal challenge is warranted. The outcomes of this study clearly indicate that a prolonged detection time from two to three hours might improve the sensitivity of the nasal challenge as a method for diagnosing aspirin intolerance. Moreover, we found a different vascular response in the nasal mucosa in the subjects with AIA after local challenge with lysine-aspirin as compared to an ATA patient group. This puts RSM-LDF as a possible new method in addition to those previously recommended for this particular test.