A Single Lung Abscess Caused by Panton-Valentine Leukocidin-Producing Methicillin-Resistant Staphylococcus aureus.

This case report presents a rare occurrence of a single lung abscess caused by Panton-Valentine leukocidin (PVL)-producing methicillin-resistant Staphylococcus aureus (MRSA) in a 38-year-old immunocompetent man. The patient, of Southeast Asian origin, presented with symptoms of fever, chest pain, cough, and shortness of breath following a recent flu-like illness. Imaging indicated a cavitary lung lesion in the left lower lobe, suggestive of a lung abscess. Initial antibiotic treatment failed, and drainage of the abscess confirmed MRSA with the PVL gene, indicating a community-acquired MRSA infection. The patient received intravenous vancomycin followed by oral linezolid, leading to the resolution of the abscess. Contact tracing and decolonization measures were implemented. This case highlights the importance of considering PVL-producing S. aureus as a potential pathogen in severe necrotizing pneumonia or sepsis and underscores the need for prompt diagnosis, appropriate antibiotic therapy, and infection control measures in managing such infections.

Kikuchi-Fujimoto disease following SARS-CoV-2 infection: A rare disease with increased incidence during the COVID-19 pandemic?

Kikuchi-Fujimoto Disease (KFD), also known as Kikuchi disease or Kikuchi histiocytic necrotizing lymphadenitis, is a rare and self-limiting condition characterized by cervical lymphadenopathy and fever, primarily affecting young Asian adults. The aetiology of KFD remains unknown, although various infectious agents have been suggested as potential triggers. With the emergence of the COVID-19 pandemic, cases of post-COVID-19 KFD and post-COVID-19 vaccine KFD have been reported. In this article, we present the first case of post-COVID-19 KFD in Hong Kong. A 24-year-old man developed fever and painful neck swelling 1 month after recovering from COVID-19. Diagnostic evaluation, including ultrasound-guided fine needle aspiration cytology (FNAC), confirmed the diagnosis of KFD. The patient's symptoms resolved spontaneously with supportive care. This case underscores the importance of considering KFD as a potential differential diagnosis in patients presenting with cervical lymphadenopathy and fever following COVID-19 recovery or vaccination.

First reported case of late recurrence of pulmonary mucormycosis in a renal transplant recipient with poorly controlled diabetes mellitus.

Pulmonary mucormycosis (PM) is a rare, life-threatening fungal infection usually affecting immunocompromised patients. Its incidence is rising, with a recent outbreak associated with COVID-19 co-infection. Amphotericin B along with early surgery are considered the standard treatment. Recurrence has been reported in patients without adequate treatment and without permanent reversal of predisposing factors. We report a case of late recurrence of PM in a renal transplant recipient. In 2012, he was diagnosed with PM. Imaging at the time showed a lingular mass. He was treated with antifungal for 1 year until complete radiological resolution. Surgical intervention was considered but no further follow-up action was taken. In 2020, he presented with fever and haemoptysis. Imaging again showed a lingular mass, which was confirmed to be PM by bronchoscopic lung biopsy. This case highlights the importance of secondary antifungal prophylaxis for PM if permanent reversal of immunosuppression is not possible.

New pneumothorax complicating successful treatment of persistent air leak by endobronchial valves.

Endobronchial one-way valves (EBV) have been proposed as a treatment option for persistent air leak (PAL) complicating spontaneous pneumothorax when surgical intervention is considered not feasible. Published case series showed this form of treatment to be generally safe. We report two such cases in which both achieved immediate cessation of air leak and post-procedural chest radiograph showed significant collapse of the treated lobe, but developed sudden onset of shortness of breath within 24 h after EBV insertion. Chest radiograph showed continued collapse of the treated lobes with enlarged ipsilateral pneumothorax in one patient and new contralateral pneumothorax in the other. Pulmonologists and thoracic surgeons inserting EBV for treatment of PAL should be aware of this possible and important complication.

Blood Eosinophil and Risk of Exacerbation in Chronic Obstructive Pulmonary Disease Patients: A Retrospective Cohort Analysis.

Purpose: Blood eosinophil is a readily available biomarker to reflect the eosinophilic inflammation in chronic obstructive pulmonary disease (COPD) patients, yet its association with exacerbation is inconclusive. It is uncertain which measurement, eosinophil percentage or absolute eosinophil count, should be used and what is the optimal cutoff for exacerbation prediction. Patients and Methods: A total of 247 COPD patients were included in this retrospective cohort study. Blood eosinophil during stable disease state, baseline demographics, and clinical characteristics in 12 months after the index complete blood count (CBC) were recorded. Exacerbation frequencies were compared between patients with high and low blood eosinophil percentage using 2% as cut-off. Logistic regression and receiver operating characteristics (ROC) curve analyses were conducted. Results: Patients with blood eosinophil ≥2% were associated with more frequent exacerbations than patients with eosinophil <2% in the 12 months after the index CBC (mean exacerbation 1.07 vs 0.34, p < 0.001). Higher blood eosinophil percentage conferred a higher risk of exacerbation. Adjusted odds ratio for exacerbation in 12 months after the index CBC for blood eosinophil ≥2% was 2.98 (95% confidence interval = 1.42-6.25). The area under the ROC curve of eosinophil percentage was significantly higher than that of absolute eosinophil count (0.678 vs 0.640, p = 0.010). The optimal cutoff of blood eosinophil percentage for exacerbation prediction was 2.8%. Conclusion: Blood eosinophilia was associated with higher exacerbation risk in COPD patients. Further studies are required to elucidate the mechanism of eosinophilic inflammation in COPD and determine the optimal treatment strategy to reduce exacerbations.

Endobronchial one-way valve for persistent air leak and lung volume reduction.

There are randomized controlled study data showing that endobronchial one-way valves (EBV) are useful for bronchoscopic lung volume reduction (BLVR). There is also case series data showing EBV to be effective in stopping persistent air leaks complicating pneumothoraces. We describe a 66-year-old man with severe chronic obstructive pulmonary disease (COPD) who failed assessments for BLVR because of the inability to perform the carbon monoxide diffusion test but subsequently had EBV deployed to his right upper lobe bronchi for persistent air leak complicating a spontaneous pneumothorax. Afterwards, there was subjective improvement in breathlessness, exercise capacity, and reduced frequency of exacerbations requiring hospitalization. Lung function parameters showed marked improvement. This case suggests that patients with compatible spirometric lung volume and computed tomography findings should proceed with BLVR. In addition, one should be aware of the possibility of improved lung function in patients with pulmonary emphysema following implantation of EBV for persistent air leak.