A 25-year-old male presented to a community hospital with the chief complaints of productive cough and shortness of breath on exertion for 2 weeks, which was associated with fever and chills. Other review of systems was unremarkable. He was initially evaluated by his primary care physician who started him on a course of azithromycin for 5 days, but his symptoms worsened after the antibiotics were done. He had a history of intravenous drug abuse in the past, but he admitted to being clean for the last 2-3 months. For the last 2 months prior to his admission, he installed television and internet routers in residences for a job, with most installations in basements that were damp and moldy. He denied history of recent travel or incarceration.
On presentation, he had temperature of 101 F, pulse of 124/min, respiratory rate of 18/min, and blood pressure of 108/58 mmHg. Oxygen saturation was 84% on room air. Physical examination revealed bibasilar crackles on auscultation of chest. Cardiac examination revealed first and second heart sounds with no murmurs, rubs, or gallops. Rest of physical examination was within normal limits.
Laboratory investigations revealed white blood count of 17,100/UL (normal 4,000-11,000/UL) with absolute neutrophil count of 15,570/UL. Chest x-ray showed bibasilar infiltrates. Computerized tomography (CT) scan of chest showed multiple cavitary and pre-cavitary lesions in both lung fields measuring 1-3 cm, as shown in Fig. 1. Differential diagnoses for the bilateral cavitary lesions were considered including septic emboli from endocarditis, tuberculosis, fungal infection as well as wegener granulomatosis. He was started empirically on vancomycin and cefepime, and the hypoxia was treated with non-invasive ventilation. The initial blood cultures were positive for methicillin-sensitive staphylococcus aureus. Sputum was negative for Acid-Fast Bacilli. Serum cryptococcal antigens were negative. His serum histoplasma antigen was negative while the urine histoplama antigen was incidentally positive, although he never lived in an endemic area for the histoplasma. He was switched to intravenous oxacillin. The transthoracic echocardiogram (TTE) was done which revealed large-sized, freely mobile vegetation on the pulmonic valve with moderate pulmonic insufficiency, as shown in Fig. 2. His subsequent blood cultures after 48 h on antibiotics were negative. Cardiothoracic surgery was consulted who decided to pursue medical management unless patient deteriorates. CT chest repeated after 2 weeks showed decrease in size of cavitary lesions. He was subsequently discharged to a skilled facility to complete 6 weeks course of intravenous antibiotics per infectious diseases recommendations. On follow-up, he was found to have complete recovery and full resolution of symptoms. Given the fact that he responded well to oxacillin, further workup such as bronchoscopy and lung biopsy for positive urine histoplasma antigen was deferred.