Abstract

Rhinitis and chronic rhinosinusitis (CRS) are frequently associated with asthma and CRS with severe asthma. Loss of smell (LoS) is associated with CRS, specially with nasal polyps.

We aimed to assess the reliability of LoS to discriminate severe from non-severe asthma and CRS from rhinitis.

In a cross-sectional study carried out in 2010-11 by pulmonologists and ENT specialists in 23 centers, asthmatic patients (N=383) were evaluated by GINA classification: 17.3% intermittent and 82.7% persistent (24.6% mild, 31.4% moderate, 26.7% severe) and by ARIA and EPOS: Half (49.6%) had rhinitis (37.0% AR and 12.6% NAR) and 36.2% CRS (16.7% CRSsNP; 19.5% CRSwNP) while 14.2% had no sinonasal disease. LoS was evaluated by severity (VAS scales, 0-100mm, median (IQR,Inter-Quartil Range)) and by prevalence of anosmia (hyposmia VAS >0-70MM, anosmia VAS >70mm).

LoS was present in 55.4% of asthma patients (hyposmia 41.5%, anosmia 14.9%). LoS severity was higher (22mm (0-75), p<0.001) and anosmia more frequent (26.4%, p<0.001) in severe persistent asthma than in moderate (10mm (0-50); 11.4%); mild (0mm (0-28); 10.7%), or intermittent asthma (0mm (0-45); 8.6%). In addition, LoS was more severe (38mm (2-76) vs. 0mm (0-45), p<0.001) and anosmia more frequent (28.1% vs. 3.9%, p<0.001) in CRS than in rhinitis, and even more severe (50mm (11-89) vs. 20mm (0-56), p<0.001) and anosmia more frequent (40.6% vs. 13.4%, p<0.001) in CRSwNP than in CRSsNP.

Loss of smell and specially the presence of anosmia may clearly discriminate severe from non-severe asthma and CRS (specially with nasal polyps) from rhinitis alone in asthma patients and may be considered a significant clinical marker of severe asthma.