Association of nasal inflammation and lower airway responsiveness in schoolchildren based on an epidemiological survey.
OBJECTIVE
We sought to increase our understanding of the rhinitis-asthma relationship and improve strategies for the treatment of patients with these diseases. The aim of this study was to identify a connection between upper airway inflammation and lower airway responsiveness.


METHODS
We counted eosinophils on nasal smears, and performed spirometry, allergic skin tests, and methacholine challenge tests in 308 schoolchildren plus a questionnaire on respiratory symptoms. The methacholine concentration causing a 20% fall in forced expiratory volume in 1 second (PC20 < 25 mg/mL) was used as the threshold of bronchial hyperresponsiveness (BHR).


RESULTS
In total, 26% of subjects had positive nasal eosinophils on a smear, and 46.2% of subjects had BHR at < 25 mg/mL methacholine PC20. Nasal symptoms were higher in subjects with than without nasal eosinophils (p = 0.012). Asthma symptoms did not differ between subjects with and without nasal eosinophils. Nasal eosinophils were higher in subjects with atopy than those without (p = 0.006), and there was no difference in PC20 methacholine according to atopy (15.5 ± 1.07 vs. 17.5 ± 0.62; p > 0.05). No difference in BHR was detected when comparing subjects with and without nasal eosinophils. There were significant differences in the PC20 between subjects with greater than 50% nasal eosinophils and without nasal eosinophils (11.01 ± 2.92 mg/mL vs. 17.38 ± 0.61 mg/mL; p < 0.001).


CONCLUSIONS
These findings demonstrated that nasal eosinophilic inflammation might contribute to lower airway responsiveness in schoolchildren, based on an epidemiological survey.
Department of Internal Medicine, Soonchunhyang University Bucheon Hospital, Bucheon, Korea.
Jun-Ho
JH
Myung
Department of Internal Medicine, Soonchunhyang University Bucheon Hospital, Bucheon, Korea.
Hyun-Jeong
HJ
Seo
Department of Internal Medicine, Soonchunhyang University Bucheon Hospital, Bucheon, Korea.
Soo-Jeong
SJ
Park
Department of Internal Medicine, Soonchunhyang University Bucheon Hospital, Bucheon, Korea.
Bo-Young
BY
Kim
Department of Internal Medicine, Soonchunhyang University Bucheon Hospital, Bucheon, Korea.
Il-Sang
IS
Shin
Department of Nursing, Montana State University, Bozeman, MT, USA.
Jun-Hak
JH
Jang
Department of Nursing, Gwangju Workers' Health Center, Gwangju, Korea.
Yun-Kyung
YK
Kim
Department of Internal Medicine, Soonchunhyang University Bucheon Hospital, Bucheon, Korea.
An-Soo
AS
Jang
D000293:Adolescent; D017677:Age Distribution; D000367:Age Factors; D001249:Asthma / Q000175:diagnosis / Q000453:epidemiology* / Q000503:physiopathology; D016535:Bronchial Hyperreactivity / Q000175:diagnosis / Q000201:enzymology* / Q000503:physiopathology; D001985:Bronchial Provocation Tests; D002648:Child; D004802:Eosinophilia / Q000175:diagnosis / Q000453:epidemiology* / Q000276:immunology; D004804:Eosinophils / Q000276:immunology; D005260:Female; D006306:Health Surveys; D006801:Humans; D007428:Intradermal Tests; D007958:Leukocyte Count; D008168:Lung / Q000503:physiopathology*; D008297:Male; D009297:Nasal Mucosa / Q000276:immunology*; D056910:Republic of Korea / Q000453:epidemiology; D012220:Rhinitis / Q000175:diagnosis / Q000453:epidemiology* / Q000276:immunology; D013147:Spirometry; D011795:Surveys and Questionnaires
Bronchial hyperreactivity; Eosinophils; Nose