Development of chronic airway obstruction in patients with eosinophilic bronchitis: a prospective follow-up study.
OBJECTIVE
Eosinophilic bronchitis (EB) presents as a chronic cough and sputum eosinophilia without airflow limitation or bronchial hyperreactivity. Its long-term clinical course remains unknown. This study evaluated how frequently EB recurs and whether it develops chronic airway obstruction.


METHODS
This study was a prospective analysis.


METHODS
Cough severity, FEV(1), provocative concentration of methacholine causing a 20% fall in FEV(1), and sputum eosinophil percentages were serially measured in 36 subjects for up to 48 months. All subjects inhaled corticosteroids until cough subsided.


RESULTS
Five of the twenty four follow-up subjects (21%) had a recurrent episode of EB 4 to 6 months after disappearance of the first episode of EB (recurrent eosinophilic bronchitis). Progressive FEV(1) reduction > 20% was observed in three of the subjects, including a subject with asthma developing at the ninth month. Nineteen subjects had no recurrence of cough (nonrecurrent eosinophilic bronchitis) and no progressive FEV(1) reduction > 20%. However, sputum eosinophilia recurred between 4 months and 24 months in 10 subjects. Mean values of FEV(1) at the ninth and 12th months of the study were significantly lower in the recurrent eosinophilic bronchitis group than in the nonrecurrent eosinophilic bronchitis group (p < 0.01).


CONCLUSIONS
These results suggest that repeated episode of EB is associated with the development of chronic airflow obstruction, including asthma.
Park
Sung-Woo
SW
Asthma and Allergy Research Group, Soonchunhyang University Hospital, Bucheon, Korea.
Lee
Young Mok
YM
Jang
An Soo
AS
Lee
June Hyuk
JH
Hwangbo
Young
Y
Kim
Do Jin
DJ
Park
Choon-Sik
CS
D000305:Adrenal Cortex Hormones / Q000627:therapeutic use; D000328:Adult; D017677:Age Distribution; D001985:Bronchial Provocation Tests / Q000379:methods; D001991:Bronchitis / Q000150:complications / Q000175:diagnosis* / Q000188:drug therapy; D002908:Chronic Disease; D003371:Cough / Q000150:complications / Q000175:diagnosis / Q000188:drug therapy; D018450:Disease Progression; D004802:Eosinophilia / Q000150:complications / Q000175:diagnosis* / Q000188:drug therapy; D005260:Female; D006801:Humans; D015994:Incidence; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D011336:Probability; D011379:Prognosis; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000453:epidemiology / Q000209:etiology*; D018570:Risk Assessment; D012720:Severity of Illness Index; D017678:Sex Distribution; D013183:Sputum / Q000166:cytology*; D018709:Statistics, Nonparametric
D000305:Adrenal Cortex Hormones