Korean J Asthma Allergy Clin Immunol.  2007 Jun;27(2):125-130.

Evaluation of the Causes of Chronic Cough with Sputum Eosinophilia

Abstract

BACKGROUND: Eosinophilic bronchitis (EB) is recently regarded as an important cause of chronic cough. However, sputum eosinophilia is commonly encountered in the other causes of chronic cough such as upper airway cough syndrome (UACS) and asthma.
OBJECTIVE
To evaluate the cause of chronic cough with sputum eosinophilia. METHOD: We investigated patients with chronic cough. Induced sputum, methacholine bronchial provocation test, skin prick test, throat examination, chest X-ray, paranasal sinus (PNS) x-ray and rhinoscopy were performed. RESULT: Sputum was induced in 287 patients. Sputum eosinophilia greater than 3% was present in 117 (40.8%) patients. Among 117 patients with sputum eosinophilia, eosinophilic asthma was diagnosed in 36 (30.8%) patients, chest X-ray abnormality or ACEI use was detected in 18 (15.4%) patients, and the remaining 63 (53.8%) patients could be considered to have EB. Among 63 patients with EB, UACS and GERD were found to be combined in 48 (76.2%) and 2 (3.2%) patients, respectively. EB alone without the other causes was diagnosed in 13 (11.1%) patients. Among total 287 patients, EB was detected in 22.0%, and EB alone without the other causes in 4.5%.
CONCLUSION
Sputum eosinophilia can be frequently detected in chronic cough. EB is the common cause in chronic cough with sputum eosinophilia. However, EB is likely to be associated with UACS, which should be considered in cases of EB. (Korean J Asthma Allergy Clin Immunol 2007;27:125-130)

MeSH Terms

Asthma
Bronchial Provocation Tests
Bronchitis
Cough*
Eosinophilia*
Eosinophils
Gastroesophageal Reflux
Humans
Hypersensitivity
Methacholine Chloride
Pharynx
Skin
Sputum*
Thorax
Methacholine Chloride