RARE PRESENTATION OF MEDIASTINAL ABSCESS SUPERINFECTION IN AN INFLUENZA B PATIENT

Abstract

SESSION TITLE: Medical Student/Resident Chest Infections Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: October 18-21, 2020 INTRODUCTION: Influenza is generally a self-limited infection, however complicated with bacterial superinfection, it has been associated with increased morbidity and mortality[1]. We present the first case report in the literature of an immunocompetent Influenza B patient complicated with methicillin-sensitive Staphylococcus aureus (MSSA) mediastinal abscess and necrotizing pneumonia. CASE PRESENTATION: A 33-year-old male patient with past medical history of asthma presented to ED with myalgias, productive cough with rusty sputum and intermittent low-grade fever for 2 weeks. Initial vitals showed temperature of 100.6 F, heart rate of 106 bpm, respiratory rate of 24 with normal blood pressure and oxygen saturation. Physical examination was unremarkable. Initial workup revealed leukocytosis with WBC of 18 k/ul. CXR showed asymmetric enlargement of the right hilum with suspicion of central mass and to further analyze CT Chest with IV contrast was done showing consolidation in the right lower lobe (RLL) with mass-like consolidation in right hilum with mediastinal extension. (Figure 1) Patient was treated empirically with Piperacillin/Tazobactam, Vancomycin and Azithromycin. Nasopharyngeal swab for Influenza B PCR came back positive and blood cultures grew MSSA after which antibiotics were de-escalated to Oxacillin. His hospital course was complicated by clinical deterioration and repeat CT Chest revealed RLL Necrotizing Pneumonia and anterior mediastinal abscess. (Figure 2) He had emergent median sternotomy with radical thymectomy and debridement of mediastinal tissues. No histological evidence of malignancy was present, and cultures grew MSSA. He improved clinically and was discharged on IV oxacillin course for 6 weeks. His follow up CT chest showed complete resolution of mediastinal and resolving RLL infiltrate. DISCUSSION: Pneumonia is considered the most common complication of influenza. It could be primary viral pneumonia or secondary to bacterial superinfection due to epithelium disruption and alteration in host immunity response. Mediastinal abscess has not been reported before in the literature as post influenza complication. Our case is first in literature for such life-threatening complication and the key to success is early imaging detection, keeping high level of suspicion when the patient is not responding appropriately to the initial therapy and aggressive surgical and medical management. CONCLUSIONS: Clinical deterioration or inappropriate response to antibiotic therapy in post influenza bacterial pneumonia should raise the suspicion for uncommon complications such as mediastinal abscess and should be investigated with advanced imaging, CT chest with IV contrast or MRI. Reference #1: Martin, C.M., et al., Asian influenza A in Boston, 1957-1958. I. Observations in thirty-two influenza-associated fatal cases. AMA Arch Intern Med, 1959. 103(4): p. 515-31. DISCLOSURES: No relevant relationships by Saira Afzal, source=Web Response No relevant relationships by Mahmoud Alwakeel, source=Web Response No relevant relationships by kuttetoor Gopalakrishna, source=Web Response No relevant relationships by Talha Saleem, source=Web Response