A randomized clinical trial comparing treatment effectiveness of azithromycin and doxycycline for pediatric Mycoplasma pneumonia.

Mycoplasma pneumoniae accounts for 10-30% of community-acquired pneumonia (CAP) in children. Proportionally, M. pneumoniae has become the most important pathogen for childhood pneumonia after the widespread use of Streptococcus pneumoniae vaccines. M. pneumoniae is routinely treated with antibiotics, and the macrolides antibiotics are the drug of choice for M. pneumonia infection. However, macrolide-resistance rates have increased to 20 and 100% in Asia. In previous studies, the most common mutation point, A2063G, was detected from 23% of local strains in Taiwan. The evolution and spreading of Mycoplasma in Taiwan and different countries are unknown. Genotyping based on multiple-locus variable-number tandem-repeat and resistance analysis (MLVA) will be used to study the classification and possibly the evolution of M. pneumoniae strains. While the macrolide-resistance is increasing, the optimal therapy remains unclear. Both tetracyclines and fluoroquinolones showed promises in treating macrolide-resistant M. pneumoniae in adults. However, their use in children is not recommended due to safety concerns. Recently, evidence are accumulating that doxycycline, unlike other tetracyclines, does not cause staining of teeth. In the current study, the investigators are going to carry out a randomized control trial to compare the efficacy and safety of doxycycline against macrolide-resistant M. pneumoniae. On the other hand, the investigators are going to update the macrolide-resistant rates in Taiwan and analyze M. pneumoniae strains in Taiwan by MLVA. By using this rapid and highly discriminatory tool, the investigators could provide more reliable information about the relationship between resistance strains

Inclusion Criteria:

• Children aged 1-18 years, admitted due to lower respiratory tract infections. Mycoplamsa pneumonia is diagnosed.
• The diagnosis is made within 72 hours after fever onset.
• The patient and his/her guardians are willing to participate the study and able to follow the instruction.

Exclusion Criteria:

• Patients who have already taken macrolides, tetracyclines, or fluoroquinolones.
• Patient's with congenital or acquired immunodeficiency.
• Severe patients who needs ICU care.
• Patients or their guardians who are not willing to participate in the study.