Objective: Chronic cough is one of the most common symptoms in children. Post infectious causes following Mycoplasma pneumoniae, Chlamydia pneumoniae and Bordetella pertussis infections play important role in development of chronic cough. Aim of this study was to evaluate M. pneumoniae and C. pneumoniae serology and diagnosis and treatment in children with chronic cough according to American College of Chest Physicians (ACCP) guideline.

Materials and Methods: Pulmonary function tests (PFTs) and chest x-rays were obtained in all patients aft er detailed medical history and physical examination. Blood specimens for M. pneumoniae, C. pneumoniae serologies were analyzed by enzyme-linked immunosorbent assay (ELISA). Patients were re-evaluated in 2-4 weeks intervals until cough disappeared.

Results: The study included 41 children, between 6 and 14 years of age. Th e mean age was 8.00 ± 1.96 year. PFTs and chest x-rays were within normal limits in all children. Th e children with wet cough, comprising 68% of the patients, received 10-day course of Clarithromycin, while those with dry cough were treated with inhaled steroid. M. pneumoniae IgM positivity was found in 17.07% (7/41), C. pneumoniae IgM positivity in 2.85% (1/35), M. pneumoniae IgM and/or IgG positivity in 41.46% (17/41), and C. pneumoniae IgM and/or IgG positivity in 25.7% (9/35) of patients. Seropositive patients with M. pneumoniae and/or C. pneumoniae were diagnosed as protracted bronchitis, upper airway cough syndrome and asthma-like disease according to the guideline.

Conclusion: In school-age children with chronic chough, M. pneumoniae and C. pneumoniae seropositivity is in high rates. Th ese microorganisms may cause chronic infl ammation in airway and this condition clinically appear as protracted bronchitis, upper airway cough syndrome and asthma-like disease.