Radiation induced pneumonitis was a likely diagnosis. However, infectious diseases were also possible causes of the patient's problems. The patient underwent bronchoscopy for transbronchial biopsy and obtaining specimens of bronchoalveolar lavage for microbiological studies. Biopsy showed findings suggestive of pneumonitis due to radiation. In addition, a PCR test for Mycobacterium avium intracellulare was positive (1).
The patient was initially given intravenous antibiotic treatment with moxifloxacin 400 mg every 12 hours as an empirical treatment to cover atypical pathogens for 10 days (2). She felt gradually improved with this treatment. She also received per os treatment with rifabutin 150 mg every 12 hours and clarithromycin 500 mg every 12 hours for 2 months (3,4). The patients's health gradually improved. A chest X-ray verified the significant improvement (Figure 2).
This patient had a pulmonary infection due to atypical mycobacteria on top of radiation-induced pneumonitis.
1. Wagner D, Young LS. Nontuberculous mycobacterial infections: a clinical review. Infection. 2004 Oct;32:257-70.
2. Tomioka H. Adjunctive immunotherapy of mycobacterial infections. Curr Pharm Des. 2004;10:3297-312.
3. Lounis N, Roscigno G. In vitro and in vivo activities of new rifamycin derivatives against mycobacterial infections. Curr Pharm Des. 2004;10:3229-38.
4. Bermudez LE, Yamazaki Y. Effects of macrolides and ketolides on mycobacterial infections. Curr Pharm Des. 2004;10:3221-8.
1. This case was prepared for our website by Konstantinos N. Fragoulis, M.D.