Late-Onset Diffuse Lung Disease in an 8-Year-Old Girl.

An 8-year-old girl presented with a 34-day history of cough, fatigue, and impaired exercise tolerance. She experienced cyanosis on exertion but denied fever, hemoptysis, hematuria, or seizures. Her perinatal and family histories were unremarkable, and she had no history of exposure to TB. A chest radiogram from a local clinic showed diffuse pulmonary lesions. Tuberculin skin test, interferon-γ release assay, and HIV antibody test results were all negative. Immunoglobulin levels and lymphocyte subsets were normal. The patient did not respond to IV azithromycin for 1 week for community-acquired pneumonia. She was transferred to our hospital because of progressive respiratory distress and hypoxemia.