TOPIC: Chest Infections TYPE: Medical Student/Resident Case Reports INTRODUCTION: Nocardia is a unique member of the order, Actinomycetales. It is a gram-positive, aerobic bacteria that is characterized by its filamentous branching that stains acid-fast. It can be found in soil and decaying vegetation, with inhalation of airborne particles being the most common mode of inoculation. Considered to be a rare, opportunistic infection, the incidence rate is approximately 500-1000 cases in the US per year (1). Although it typically leads to cutaneous disease, Nocardia has the ability to disseminate as widespread disease leading to pulmonary and CNS involvement. CASE PRESENTATION: An 81 year old African-American female with a past medical history of non-Hodgkin Lymphoma treated with radiation in 1999, hypertension, diabetes, hypothyroidism, chronic kidney disease, and heart failure with preserved ejection fraction. She presented with worsening dyspnea, orthopnea, and lower extremity swelling and was admitted for heart failure exacerbation. She was found to have multiple, painful skin abscesses. On presentation, she was septic: febrile and tachycardic with profound leukocytosis. Radiographic imaging revealed multiple, large, cystic fluid collections in the neck, bilateral arms, and left leg along with right, hilar lymphadenopathy and apical cavitary lesion in the right lung. There was a large, anterior chest wall mass communicating with the left arm lesion. IR guided biopsy ruled-out malignancy. General surgery performed I&D's of the peripheral lesions whereas Cardiothoracic Surgery performed I&D of the chest wall mass. Aerobic cultures grew gram-positive, branching bacilli that later speciated to Nocardia pneumoniae. DISCUSSION: The patient was diagnosed with Disseminated Nocardiosis with lymphocutaneous and pulmonary involvement. Our work-up was negative for CNS or bone disease. The exact etiology was unclear. She did not endorse direct trauma/inoculation at lesion sites and denied any unusual exposure to soil, decaying vegetation, or aquatic environments. Despite Nocardia's prevalence in immunocompromised hosts, our patient was determined to be immunocompetent. Fortunately, there was no evidence of recurrence of malignancy and she was HIV negative. Her treatment regimen consisted of a dual agent induction therapy for 6 weeks that was followed by a 6 month maintenance period with a single agent. However, Nocardia has a propensity to recur or progress despite appropriate antibiotic therapy and source control. CONCLUSIONS: Nocardiosis has been described as an emerging infectious disease given the higher number of HIV and transplant patients. Notably, Nocardia pneumoniae is not accounted for in 82 percent of US strains isolated between 1995 and 2004 (2). This species was first described in 2004 with either "undetermined clinical significance" versus "pulmonary disease" (3). This would be a novel presentation of disseminated Nocardia pneumoniae in an immunocompetent host. REFERENCE #1: Rawat D, Rajasurya V, Chakraborty RK, et al. Nocardiosis. [Updated 2020 Aug 10]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK526075/ REFERENCE #2: Uhde KB, Pathak S, McCullum I Jr, et al. Antimicrobial-resistant nocardia isolates, United States, 1995-2004. Clin Infect Dis 2010; 51:1445. REFERENCE #3: The Complexities of Nocardia Taxonomy and IdentificationPatricia S. Conville, Barbara A. Brown-Elliott, Terry Smith, Adrian M. ZelaznyJournal of Clinical Microbiology Dec 2017, 56 (1) e01419-17; DOI: 10.1128/JCM.01419-17 DISCLOSURES: No relevant relationships by HUY NONG, source=Web Response No relevant relationships by Michael Vu, source=Web Response