RESUMO
BACKGROUND: The safety and utility of nasal provocation tests with lysine-aspirin (L-ASA) in the diagnosis of aspirin-intolerant asthma (AIA) have previously been described in a short series of patients. OBJECTIVES: To describe the clinical features and safety of an L-ASA challenge test in patients with AIA. METHODS: We evaluated 72 patients (79% women), with a mean ± SD age of 47.9 ± 14.5 years. All patients were submitted to an L-ASA nasal provocation test (29 mg in each nostril) under acoustic rhinometry (AcR) control. Symptom score (0-3), visual analogical scale and nitric oxide determinations were performed at baseline and at 15, 30, 60 and 90 min. A decrease in nasal volume of at least 25% was considered a positive test. Nasal nitric oxide (nNO) and forced expiratory volume in 1 s were measured. RESULTS: Nasal congestion and rhinorrhea represented 51 and 32%, respectively, of total symptoms. According to AcR data, the L-ASA challenge test was positive in 20% of patients at 15 min, an additional 36% were positive at 30 min, 18% at 60 min, and the remaining 26% at 90 min. nNO nasal values decreased but did not reach statistical significance. No pulmonary or systemic reactions were observed. CONCLUSIONS: Symptoms of nasal congestion associated with the reduction in nasal volume measured by AcR are the most useful parameters for establishing the diagnosis of AIA using the L-ASA nasal challenge. The method is very well tolerated and can be safely used even in patients with severe asthma.