Abstract Pulmonary Actinomycosis is a rare and insidious infectious process that encompasses only 15% of Actinomycosis. Risk factors include poor oral hygiene, HIV, foreign body aspiration, lung structural changes, and immunosuppression. A male in his early 40’s with history of intravenous drug use and smoking arrives to emergency department complaining of progressive shortness of breath, chest pain, intermittent episodes of fever, night sweats, cough. weight loss, and chills of more than 1-month in progression. The patient reports no precipitating event or associated factors. He denied hemoptysis or sputum production. On admission, vital signs showed blood pressure of 101/89 mmHg, respiratory rate of 28 breaths/min, heart rate of 102 bpm, and oxygen saturation of 96% on room air. The patient appeared frail with poor dentition and hygiene. Chest examination revealed markedly reduced breath sounds over the right hemithorax, without crackles, stridor, or wheezes. The trachea was midline. The remainder of the physical examination was unremarkable. Laboratory studies showed no leukocytosis, with 12% bandemia and anemia (hemoglobin 11 g/dL). Inflammatory markers were elevated: ESR 40 mm/hr, CRP 300 mg/L, and procalcitonin 23 ng/mL. Infectious work-up was negative for HIV but positive for HCV. Blood cultures showed no microbial growth. The initial chest radiograph demonstrated near complete right lung opacification. Contrast-enhanced chest CT revealed an 18 × 19×16 cm fluid collection with air-fluid levels and leftward mediastinal shift, consistent with a right-sided empyema involving the middle and lower lobes. Empiric intra-venous antibiotics with vancomycin, cefepime, and metronidazole were provided. However, the patient’s condition rapidly deteriorated leading to respiratory failure and subsequent endo-tracheal intubation. A chest tube was inserted, and subsequent empyema cultures revealed isolated Schaalia odontolyticus. Anti-microbic coverage was tailored to cultures with ampicillin-sulbactam for a total of 14 days with marked improvement. The patient left against medical advice after 14 days of hospitalization. Schaalia-induced complicated pneumonia is a rare, slow-progressing lung infection that can cause extensive pulmonary scarring and, through its clinical course, often mimics malignancy. Approximately 50% of pulmonary actinomycosis present with cavitations or empyema; however, such extensive empyema has not been described in literature since most cases are detected earlier and diagnosed via neoplastic work-up. This case highlights both the subtle presentation of pulmonary actinomycosis - even in the setting of extensive infection- and the severe consequences of delayed recognition. This abstract is funded by: none
Ventosa et al. (Fri,) studied this question.