We present the case of a man in his early 50s who presented with a history of fever, malaise and jaundice. Initial investigations showed liver and renal dysfunction with no discernible cause for the septic process. On starting intravenous antibiotics, the patient developed a septic-shock-like reaction requiring transfer to intensive care. A diagnosis of leptospirosis was eventually established through an extensive and thorough history leading to a stepwise approach to investigations. Treatment targeting leptospirosis was delivered with noticeable clinical improvement.

We present the first published case of simultaneous pneumonitis and immune thrombocytopenic purpura secondary to primary cytomegalovirus (CMV) infection in an immunocompetent patient. Treatment with oral valganciclovir for 2 weeks successfully led to complete clinical recovery. CMV is traditionally associated with infection in immunocompromised patients and neonates; however, evidence of severe CMV infections in immunocompetent hosts is emerging. It is important to highlight the broad range of clinical presentations of CMV infections to prevent diagnostic delay and associated morbidity and expense.

Mucosa-associated lymphoid tissue (MALT) lymphoma is an uncommon extranodal low-grade B-cell lymphoma. Pulmonary MALT lymphomas originate from bronchial MALT and are also referred to as bronchial-associated lymphoid tissue lymphomas. MALT lymphomas of the lung are slow-growing tumours and usually present as asymptomatic chronic alveolar opacities visible on chest radiographs or with non-specific pulmonary symptoms. Here we described a case of a male patient in his early 50s with cough and chest pain for 4 years. His CT chest scan showed consolidation in the lingula and left lower lobe. Histopathology of the specimen obtained from cryobiopsy of the lung lesion showed a dense monomorphic lymphoid infiltrate, and immunohistochemistry confirmed the diagnosis of MALT lymphoma. The prognosis of pulmonary MALT lymphomas is good with >80% 5-year survival rates. This case highlights that MALT lymphoma should be considered as a differential diagnosis while evaluating cases with non-resolving consolidation.

Lemierre syndrome (LS) is referred to as the \'forgotten Disease\' owing to its rarity in the postantibiotic era with an estimated yearly incidence of 1/million population. The classic triad of LS includes internal jugular vein thrombosis, oropharyngeal infection and metastatic septic emboli. We present a case of typical LS with Fusobacterium and Prevotella infection, presenting with peritonsillar abscess and jugular vein thrombosis complicated by sepsis, acute hypoxic respiratory failure due to multiple pulmonary emboli and severe thrombocytopaenia in the absence of disseminated intravascular coagulation.

Methaemoglobinaemia occurs when iron in haemoglobin is oxidised into a form that cannot transport oxygen. At low levels, it is asymptomatic, though at rising levels symptoms arise from impaired oxygenation, and it can ultimately be fatal. While uncommon, it is important to consider in hypoxaemic COVID-19 patients, especially if they are not clinically improving on standard treatments and workup for other causes does not explain the ongoing hypoxaemia. It is often diagnosed through a mismatch in peripheral and arterial oxygen, with the former typically less than the latter. We present the case of a COVID-19 patient who was found to have methaemoglobinaemia due to dapsone use for Pneumocystic jirovecii pneumonia (PJP) prophylaxis while on chemotherapy. Dapsone was stopped and supplemental high-flow nasal cannula was provided, and methaemoglobin levels improved over a 5-day period. She was discharged to follow-up with her haematologist in the clinic.

A man in his 50s, with a history of night sweats and weight loss, presented acutely with dyspnoea and chest pain. Imaging revealed right middle lobe consolidation and a large pericardial effusion. The diagnosis of actinomycosis was made using endobronchial ultrasound-guided sampling from the pericardial effusion. An orthopantomogram demonstrated that the source was a large cavity in the left lower wisdom tooth. This tooth was extracted before the completion of his antibiotic course, and the patient made a full recovery. Cardiac actinomycosis is rare, and there are few case reports describing endobronchial ultrasound-guided sampling of pericardial fluid.

Chylothorax is a rare condition caused by pleural effusion resulting from thoracic duct injury. Recurrent chylothorax is often resistant to conservative treatment and presents a clinical conundrum in its management. Here, we report a compelling case of recurrent chylothorax that persisted despite the administration of total parenteral nutrition, octreotide and thoracic duct embolisation. The patient eventually required thoracic duct ligation and talc pleurodesis, which resulted in the resolution of the effusion. Our case is an illustrative example of the effective multidisciplinary management of recurrent bilateral idiopathic chylothorax.

A woman in her 70s with a history of nodular bronchiectatic Mycobacterium avium complex pulmonary disease (MAC-PD) presented with an exacerbated productive cough and worsening findings on chest imaging. Although repeated sputum culture tests were negative for acid-fast bacilli and only revealed normal respiratory flora, a bronchoscopy identified Nocardia sp. Consequently, she was diagnosed with pulmonary nocardiosis and was successfully treated with levofloxacin. It is known that pulmonary nocardiosis can manifest in immunocompetent individuals with bronchiectasis. For cases of refractory nodular bronchiectatic MAC-PD, it is vital to consider bronchoscopy to identify potential co-infections, such as Nocardia.

Pulmonary sequestration is a rare congenital condition. It is a dysplastic lung tissue with a separate systemic blood supply and without a bronchial tree connection. The emergence of a superimposed infection can lead to its diagnosis, such as Staphylococcus aureus, Pseudomonas aeruginosa, Nocardia asteroids and Aspergillus sp pneumonia. Mycobacterium avium complex (MAC) superimposed disease is exceedingly rare. We report a case of a man in his third decade without known medical disorders presenting with a persistent cough. After an extensive microbiological workup, an MAC infection was diagnosed. An elevated carbohydrate antigen 19-9 (CA 19-9) was also noted. He was treated with antimycobacterial therapy and lobectomy resulting in clinical improvement and CA19-9 normalisation. This case illustrates the value of comprehensive microbiological investigations in patients with chronic respiratory symptoms and imaging findings that are not typical of bacterial pneumonia. Clinical studies remain needed to investigate the utility of CA 19-9 in a scoring system to guide MAC therapy.

Idiopathic hypereosinophilic syndrome is characterised by the overproduction of eosinophils with tissue infiltration, leading to multiorgan dysfunction. Its heterogenous presentation makes the diagnosis challenging and easy to miss. A woman in her 70s was admitted with chest pain and shortness of breath. Diagnostic testing showed elevated cardiac enzymes, an ejection fraction of 45% and pericardial effusion. Pericardiocentesis helped her symptoms significantly. Cardiac catheterisation revealed patent coronary arteries. She was diagnosed with myopericarditis and discharged on non-steroidal anti-inflammatory drugs. She returned the following week with worsening chest pain, dyspnoea and diarrhoea. Chest imaging showed bilateral infiltrates. Diagnostic testing showed eosinophilic predominance in peripheral blood (59%), pericardial fluid (37%) and bronchoalveolar lavage (31%). After a negative infectious workup, she was started on glucocorticoids and responded favourably. She was discharged on steroids. Mepolizumab was initiated outpatient, and steroids were discontinued. Mepolizumab was discontinued after 2 years while monitoring her symptoms and eosinophil counts.