A Case of Acute Pulmonary Edema in Scrub Typhus: A Rare Complication with Normal Cardiac and Renal Function

A Case of Acute Pulmonary Edema in Scrub Typhus: A Rare Complication with Normal Cardiac and Renal Function | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Case Report A Case of Acute Pulmonary Edema in Scrub Typhus: A Rare Complication with Normal Cardiac and Renal Function Kajananan Sivagurunathan, Nishadi Perera, Anuranga Senanayake This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6910447/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 11 Nov, 2025 Read the published version in BMC Infectious Diseases → Version 1 posted 14 You are reading this latest preprint version Abstract Background: Scrub typhus is a mite-borne rickettsial infection endemic to parts of Asia, including Sri Lanka, with a wide range of clinical manifestations. Case presentation: We report a rare case of a 16-year-old male who presented with a seven-day febrile illness complicated by hypoxemia and pulmonary congestion. Clinical examination revealed eschar and inguinal lymphadenopathy, leading to a diagnosis of scrub typhus. Despite initial suspicion of myocarditis, cardiac and renal evaluations were normal, and the patient rapidly improved with doxycycline and low-dose frusemide. The clinical course, absence of organ dysfunction, and prompt radiological resolution supported a diagnosis of noncardiogenic pulmonary edema unrelated to ARDS. Conclusion: This case highlights scrub typhus as a rare cause of pulmonary edema occurring in the absence of cardiac and renal involvement, underscoring the need for clinical awareness in endemic regions. Scrub typhus Noncardiogenic pulmonary edema Rickettsial infection Figures Figure 1 Figure 2 Figure 3 Background Scrub typhus, caused by Orientia tsutsugamushi , is a mite-borne rickettsial infection endemic to the Asia-Pacific region, including Sri Lanka [ 1 – 2 ]. It is transmitted to humans through the bite of larval trombiculid mites ("chiggers") [ 2 ]. A study from northern Sri Lanka reported that 84.4% of patients with clinical features of rickettsial illness were seropositive for scrub typhus, with most exhibiting a characteristic eschar [ 3 ]. Scrub typhus can present with a wide clinical spectrum, from asymptomatic infection to severe illness involving multiorgan dysfunction, shock, and even fatal outcomes [ 4 ]. Pleuropulmonary involvement in scrub typhus has been well documented in the literature, with reported manifestations including pleural effusion, pneumonia, interstitial pneumonitis, and acute respiratory distress syndrome (ARDS) [ 5 ]. In scrub typhus, cardiac dysfunction is recognized to contribute to the development of pulmonary edema [ 6 ]. However, acute pulmonary edema in the absence of overt cardiac or renal pathology is an exceedingly rare presentation. We present a rare case of scrub typhus in a previously healthy adolescent male who developed acute pulmonary edema without evidence of myocarditis or renal impairment. This case highlights the importance of early recognition of atypical respiratory complications of scrub typhus and the need for a high index of suspicion in endemic regions. Case presentation A 16-year-old male was transferred from a local hospital for further management of a febrile illness lasting seven days, that was complicated by respiratory distress. His illness began with a continuous high-grade fever associated with chills, rigors, headache, and body aches. There were no focal symptoms such as productive cough, urinary symptoms, or diarrhea. On the second day of fever, he sought treatment at an outpatient clinic, but his symptoms persisted. By day five, his fever remained unresolved, and he developed a poor appetite, vomiting, and reduced oral intake, prompting admission to a local hospital. He was started on 625 mg of oral coamoxiclav every 8 hours. On day six at the local hospital, he developed a marginally low blood pressure of 88/56 mmHg and was treated with intravenous saline, which improved his BP to 98/60 mmHg. However, later that night, he developed respiratory distress with an SpO₂ of 88%, leading to his transfer to our District General Hospital. On arrival, the patient appeared ill, with a respiratory rate of 24 breaths/min and an SpO₂ of 89% on room air. Auscultation revealed few bilateral basal crepitations, but there was no elevated JVP or pedal edema. His vital signs were relatively stable, with a blood pressure of 102/60 mmHg and a heart rate of 134 bpm. On detailed examination, an eschar was found on the right buttock, leading to a clinical diagnosis of scrub typhus (Figure-1). He also had right inguinal lymphadenopathy, further supporting the diagnosis. He was promptly started on 200mg of oral doxycycline. Given his respiratory distress, the initial differentials included scrub typhus myocarditis with cardiogenic pulmonary edema and scrub typhus pneumonitis. A bedside ultrasound scan of the chest revealed bilateral mild pleural effusions with significant B-lines, suggesting pulmonary interstitial involvement, but there was no consolidation. Bedside echocardiography performed by the emergency team revealed mild global hypokinesia, whereas electrocardiogram revealed sinus tachycardia without abnormal T or ST changes or arrhythmias (Figure-2). His chest X-ray revealed upward diversion of pulmonary vessels, and bilateral pulmonary hilar congestion with a bat-wing appearance, suggesting pulmonary edema (Figure-3-A). A working diagnosis of scrub typhus-associated myocarditis with pulmonary edema was made, and the patient was given oxygen via a face mask and intravenous frusemide 20 mg. Within three hours, his respiratory distress improved, his SpO₂ increased to 96% on room air, his respiratory rate normalized to 18 breaths/min, and his heart rate decreased to 102 bpm. However, a formal cardiology echocardiogram later revealed normal left ventricular function with no evidence of myocarditis, and troponin levels were within normal limits, making cardiogenic pulmonary edema unlikely. Given his good urine output and normal serum creatinine levels, renal failure as a contributing factor was also ruled out. Although BNP was unavailable, the diagnosis of noncardiogenic pulmonary edema was made on the basis of the remaining clinical evidence. The results of the patient’s blood tests are summarized in Table 1 . Table 1 Summary of the laboratory test results of the patient. Laboratory test Result Normal range White cell count 4.07 × 10 9 /L 4.0–10.0 × 10 9 /L Hemoglobin 12.1 g/dL 12–15 g/dL Platelets 76 × 10 9 /L 150–400 × 10 9 /L C-Reactive protein 91 mg/L 0–3 mg/L Aspartate transferase 95.5 U/L 15–37 U/L Alanine aminotransferase 119.4 U/L 16–63 U/L Sodium 137 mmol/L 136–145 mmol/L Potassium 3.94 mmol/L 3.5–5.1 mmol/L Creatinine 0.81 mg/dL 0.7–1.3 mg/dL Urea 23.3 mg/dL 18–55 mg/dL Prothrombin time 13.4 sec 11-13.5 sec His diuretic therapy was continued for 48 hours before discontinuation. Doxycycline was continued at 200 mg every 12 hours for 48 hours, followed by 100 mg every 12 hours for the next eight days. He was monitored in the ICU for 24 hours before being transferred to the medical ward. His fever resolved within 36 hours of admission. A repeat chest X-ray performed after 48 hours of diuretic therapy showed significant improvement (Figure-3-B). He made an uneventful recovery before being discharged in stable condition. The Weil-Felix test result, which is not immediately available due to processing time, was received two weeks after presentation and revealed a high OXK titer of 1:1280, supporting the diagnosis of scrub typhus. Discussion Orientia tsutsugamushi , is an obligate intracellular gram-negative bacterium transmitted by the bite of infected chigger larvae of Leptotrombidium mites [ 2 ]. Following inoculation, the bacteria replicate locally, leading to the development of a papule that subsequently ulcerates and forms a necrotic eschar. One of the earliest and most characteristic clinical signs of scrub typhus is eschar. While its presence is highly suggestive of scrub typhus, it is often overlooked because of its painless nature and hidden locations, such as the groin, axilla, or buttocks, especially in dark-skinned individuals [ 2 ]. In endemic regions such as Sri Lanka, the identification of an eschar remains vital for early diagnosis, as demonstrated in our case. Eschar is often accompanied by regional lymphadenopathy, which can progress to generalized lymph node enlargement within a few days [ 7 ]. Humans typically develop an acute febrile illness within 8–10 days following a chigger bite, with bacteraemia preceding the onset of fever by approximately 1–3 days [ 8 ]. Like other rickettsial infections, scrub typhus is characterized by perivascular inflammation affecting small blood vessels. Although endothelial cells are involved, histopathological findings suggest the involvement of macrophages in the disease process [ 9 ]. Scrub typhus may disseminate into multiple organs through endothelial cells and macrophages, resulting in the development of fatal complications [ 7 ]. The presence of pleuropulmonary involvement in patients with scrub typhus has been well documented in the literature. The pathophysiology is thought to involve direct infection of the pulmonary endothelium, immune-mediated injury, and systemic inflammatory responses. However, pulmonary edema in the absence of cardiac or renal dysfunction is exceedingly rare. In our patient, the initial suspicion of myocarditis was based on mild global hypokinesia observed via bedside echocardiography. This was later ruled out by formal echocardiographic assessment, which revealed preserved left ventricular function and normal troponin levels. Renal function was also normal, and urine output remained adequate throughout, excluding volume overload secondary to renal failure. The constellation of findings—including eschar, serological confirmation, bilateral pulmonary involvement, and absence of cardiac or renal pathology—strongly supported a diagnosis of scrub typhus–associated noncardiogenic pulmonary edema due to capillary leak syndrome. ARDS is the most common cause of noncardiogenic pulmonary edema; however, distinguishing it from other forms of noncardiogenic pulmonary edema can be clinically challenging. ARDS is characterized by the acute onset of hypoxemia, bilateral infiltrates on chest imaging, and the absence of left heart failure, often requiring mechanical ventilation. In contrast, although our patient presented with pulmonary congestion on chest radiography and hypoxemia, the clinical course and rapid response to diuretic therapy supported a diagnosis of noncardiogenic pulmonary edema unrelated to ARDS. ARDS typically evolves over days and responds more slowly to treatment. A few cases in the literature describe noncardiogenic pulmonary edema in patients with scrub typhus [ 10 ]. Interestingly, our patient’s respiratory distress improved rapidly following the administration of low-dose intravenous frusemide. Although capillary leak syndrome–related pulmonary edema is typically noncardiogenic and may not respond well to diuretics, this case highlights that diuretics may provide symptomatic relief in selected, hemodynamically stable patients with evidence of pulmonary congestion. In such situations, the cautious use of low-dose diuretics may help mobilize extravascular lung fluid without compromising intravascular volume status. The prompt clinical improvement in our patient supports this approach, suggesting that even in noncardiogenic pulmonary edema, supportive diuresis may be beneficial in carefully selected cases. Timely treatment remains the cornerstone of scrub typhus management. Doxycycline is the first-line treatment for scrub typhus and is considered highly effective [ 11 ]. Azithromycin is an alternative, particularly for patients with contraindications to doxycycline, such as pregnant women or young children [ 12 ]. Our patient showed a favorable response to doxycycline, with marked clinical improvement within 48 hours, which was consistent with expected treatment outcomes. Conclusion This case emphasizes the need to maintain a high index of suspicion for scrub typhus in patients presenting with fever and respiratory symptoms, especially in endemic regions. Although pulmonary edema is an uncommon manifestation, it can occur even in the absence of cardiac or renal dysfunction. Recognizing this rare presentation is crucial for timely diagnosis and management. Furthermore, low-dose diuretics may provide symptomatic benefits in carefully selected, hemodynamically stable patients with noncardiogenic pulmonary edema not related to ARDS. Abbreviations ARDS acute respiratory distress syndrome Declarations Ethics approval and consent to participate Not applicable Clinical Trial Not applicable Consent for publication Informed written consent was obtained from the patient’s father for publication of this case report and accompanying images. Availability of data and materials The information used in preparing this case report was obtained from the patient’s bed head ticket at the District General Hospital Kilinochchi, Sri Lanka. This report does not contain any patient data that could compromise privacy. Relevant data can be made available by the corresponding author upon reasonable request, subject to ethical and institutional guidelines. Competing interests The authors declare that they have no competing interests. Funding This case report did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. Authors Contributions KS contributed substantially to the clinical management, conception and design of the work, acquisition, analysis, and interpretation of data, and drafting and revision of the manuscript. NP contributed substantially to the clinical management, conception and design of the work, acquisition, analysis, and interpretation of data, and drafting and revision of the manuscript. AS contributed substantially to the clinical management, conception and design of the work, acquisition, analysis, and interpretation of data, and drafting and revision of the manuscript. All authors approved the submitted version of the manuscript and agree to be personally accountable for their own contributions and to ensure the accuracy and integrity of the work. Acknowledgement Not applicable References Kelly DJ, Fuerst PA, Ching WM, Richards AL. Scrub typhus: the geographic distribution of phenotypic and genotypic variants of Orientia tsutsugamushi. Clin Infect Dis. 2009;48:S203–30. 10.1086/596576 . Clinical Overview of Scrub Typhus. (2024). https://www.cdc.gov/typhus/hcp/clinical-overview/clinical-overview-of-scrub-typhus.html . Accessed: 25/04/2025. Pradeepan JA, Ketheesan N, Murugananthan K. Emerging scrub typhus infection in the northern region of Sri Lanka. BMC Res Notes. 2014;7:719. 10.1186/1756-0500-7-719 . Devamani C, Alexander N, Chandramohan D, et al. Incidence of Scrub Typhus in Rural South India. N Engl J Med. 2025;392:1089–99. 10.1056/nejmoa2408645 . Wiwanitkit S, Wiwanitkit V. Pleuropulmonary scrub typhus: a summary of Thai cases. J Vector Borne Dis. 2012;49:48. Lin SY, Matsuno Y, Yokosawa M, et al. Analysis of scrub typhus involvement of the lung by bronchoalveolar lavage: A case report. Respiratory Invest. 2016;54:487–9. 10.1016/j.resinv.2016.06.004 . Scrub Typhus. (2023). https://emedicine.medscape.com/article/971797-overview#a4 . Accessed: 25/04/2025. Shirai A, Saunders JP, Dohany AL, Huxsoll DL, Groves MG. Transmission of scrub typhus to human volunteers by laboratory-reared chiggers. Jpn J Med Sci Biol. 1982;35:9–16. 10.7883/yoken1952.35.9 . Suputtamongkol Y, Suttinont C, Niwatayakul K, et al. Epidemiology and clinical aspects of rickettsioses in Thailand. Ann N Y Acad Sci. 2009;1166:172–9. 10.1111/j.1749-6632.2009.04514.x . Zhou XL, Ye QL, Chen JQ, Li W, Dong HJ. Manifestation of acute peritonitis and pneumonedema in scrub typhus without eschar: A case report. World J Clin cases. 2021;9:6900–6. 10.12998/wjcc.v9.i23.6900 . Song JH, Lee C, Chang WH, et al. Short-course doxycycline treatment versus conventional tetracycline therapy for scrub typhus: a multicenter randomized trial. Clin Infect diseases: official publication Infect Dis Soc Am. 1995;21:506–10. 10.1093/clinids/21.3.506 . Kim YS, Lee HJ, Chang M, Son SK, Rhee YE, Shim SK. Scrub typhus during pregnancy and its treatment: a case series and review of the literature. Clin Infect diseases: official publication Infect Dis Soc Am. 2006;75:955–9. 10.4269/ajtmh.2006.75.955 . Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 11 Nov, 2025 Read the published version in BMC Infectious Diseases → Version 1 posted Editorial decision: Revision requested 11 Aug, 2025 Reviews received at journal 03 Aug, 2025 Reviews received at journal 28 Jul, 2025 Reviews received at journal 25 Jul, 2025 Reviewers agreed at journal 25 Jul, 2025 Reviewers agreed at journal 24 Jul, 2025 Reviewers agreed at journal 22 Jul, 2025 Reviews received at journal 19 Jul, 2025 Reviewers agreed at journal 16 Jul, 2025 Reviewers invited by journal 15 Jul, 2025 Editor invited by journal 20 Jun, 2025 Editor assigned by journal 18 Jun, 2025 Submission checks completed at journal 18 Jun, 2025 First submitted to journal 17 Jun, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-6910447","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Case Report","associatedPublications":[],"authors":[{"id":474611364,"identity":"2eddd2b7-e112-407f-a611-37dd7152df82","order_by":0,"name":"Kajananan Sivagurunathan","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA20lEQVRIie2RsQrCMBRFHwi6pGSTiIX8wisFcSj4K3Wpa8eOTp1aXBU/wUUodC50bXCtuPQDFDrWQbCpu8komLO8BO4h9xEAg+EXIQAIyAiVFz/UViLPnm2lgpoKQBV4WMiDjsKTsgmfcUncy2ndNgicTovvCooYnbRXFvUjY30x53D0FQoFRGtQxFkqPt4UCt9NWucli+1F1mkpIBJ0SRUQpGmu9wpWVejakUdYbeVLH5l6F55scueObEV3Irt2kcfpXFUMYPz5DDYkmTIuGTXDoIVW2mAwGP6QN8EbQ83Q7ifaAAAAAElFTkSuQmCC","orcid":"","institution":"District General Hospital Kilinochchi","correspondingAuthor":true,"prefix":"","firstName":"Kajananan","middleName":"","lastName":"Sivagurunathan","suffix":""},{"id":474611365,"identity":"415ead32-cc79-469b-a7c2-4f7b1ef4d41d","order_by":1,"name":"Nishadi Perera","email":"","orcid":"","institution":"District General Hospital Kilinochchi","correspondingAuthor":false,"prefix":"","firstName":"Nishadi","middleName":"","lastName":"Perera","suffix":""},{"id":474611366,"identity":"efec50ee-6b2f-4ae9-9464-9ad522f1f006","order_by":2,"name":"Anuranga Senanayake","email":"","orcid":"","institution":"District General Hospital Kilinochchi","correspondingAuthor":false,"prefix":"","firstName":"Anuranga","middleName":"","lastName":"Senanayake","suffix":""}],"badges":[],"createdAt":"2025-06-17 05:23:23","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-6910447/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6910447/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1186/s12879-025-12008-9","type":"published","date":"2025-11-11T15:57:01+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":86299067,"identity":"b2da2bfa-0aab-4131-92d3-124db11b9c45","added_by":"auto","created_at":"2025-07-09 06:01:34","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":89294,"visible":true,"origin":"","legend":"\u003cp\u003eEschar on the right buttock in this patient with scrub typhus, with the scab accidentally removed, serving as a key diagnostic clue.\u003c/p\u003e","description":"","filename":"1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6910447/v1/fd74d81a99c8601b3b3bda3f.jpg"},{"id":86299068,"identity":"bf63ae50-01bd-45f8-a4f1-eec6339ccc0d","added_by":"auto","created_at":"2025-07-09 06:01:35","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":91916,"visible":true,"origin":"","legend":"\u003cp\u003eElectrocardiogram of this patient showing sinus tachycardia without abnormal T or ST changes or arrhythmias.\u003c/p\u003e","description":"","filename":"2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6910447/v1/367ddf8993aedcbab93cca84.jpg"},{"id":86299055,"identity":"c00ca56d-4c02-406b-9370-ed656d6b8d26","added_by":"auto","created_at":"2025-07-09 06:01:26","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":80052,"visible":true,"origin":"","legend":"\u003cp\u003eSerial chest X-rays of this patient with scrub typhus. (A) Initial radiograph showing upward diversion of pulmonary vessels, bilateral hilar congestion with bat-wing appearance, suggestive of pulmonary edema. (B) Follow-up imaging after 48 hours\u003c/p\u003e","description":"","filename":"3.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6910447/v1/95fdaae0097138f91bf2cb07.jpg"},{"id":96104953,"identity":"80d20cc0-183b-4551-a505-9e83bc4431dc","added_by":"auto","created_at":"2025-11-17 16:03:36","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":706003,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6910447/v1/49962dee-137b-432d-907d-9805c8c3797d.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"A Case of Acute Pulmonary Edema in Scrub Typhus: A Rare Complication with Normal Cardiac and Renal Function","fulltext":[{"header":"Background","content":"\u003cp\u003eScrub typhus, caused by \u003cem\u003eOrientia tsutsugamushi\u003c/em\u003e, is a mite-borne rickettsial infection endemic to the Asia-Pacific region, including Sri Lanka [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. It is transmitted to humans through the bite of larval trombiculid mites (\"chiggers\") [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. A study from northern Sri Lanka reported that 84.4% of patients with clinical features of rickettsial illness were seropositive for scrub typhus, with most exhibiting a characteristic eschar [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. Scrub typhus can present with a wide clinical spectrum, from asymptomatic infection to severe illness involving multiorgan dysfunction, shock, and even fatal outcomes [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. Pleuropulmonary involvement in scrub typhus has been well documented in the literature, with reported manifestations including pleural effusion, pneumonia, interstitial pneumonitis, and acute respiratory distress syndrome (ARDS) [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. In scrub typhus, cardiac dysfunction is recognized to contribute to the development of pulmonary edema [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. However, acute pulmonary edema in the absence of overt cardiac or renal pathology is an exceedingly rare presentation.\u003c/p\u003e\u003cp\u003eWe present a rare case of scrub typhus in a previously healthy adolescent male who developed acute pulmonary edema without evidence of myocarditis or renal impairment. This case highlights the importance of early recognition of atypical respiratory complications of scrub typhus and the need for a high index of suspicion in endemic regions.\u003c/p\u003e"},{"header":"Case presentation","content":"\u003cp\u003eA 16-year-old male was transferred from a local hospital for further management of a febrile illness lasting seven days, that was complicated by respiratory distress. His illness began with a continuous high-grade fever associated with chills, rigors, headache, and body aches. There were no focal symptoms such as productive cough, urinary symptoms, or diarrhea. On the second day of fever, he sought treatment at an outpatient clinic, but his symptoms persisted. By day five, his fever remained unresolved, and he developed a poor appetite, vomiting, and reduced oral intake, prompting admission to a local hospital. He was started on 625 mg of oral coamoxiclav every 8 hours.\u003c/p\u003e\u003cp\u003eOn day six at the local hospital, he developed a marginally low blood pressure of 88/56 mmHg and was treated with intravenous saline, which improved his BP to 98/60 mmHg. However, later that night, he developed respiratory distress with an SpO₂ of 88%, leading to his transfer to our District General Hospital. On arrival, the patient appeared ill, with a respiratory rate of 24 breaths/min and an SpO₂ of 89% on room air. Auscultation revealed few bilateral basal crepitations, but there was no elevated JVP or pedal edema. His vital signs were relatively stable, with a blood pressure of 102/60 mmHg and a heart rate of 134 bpm. On detailed examination, an eschar was found on the right buttock, leading to a clinical diagnosis of scrub typhus (Figure-1). He also had right inguinal lymphadenopathy, further supporting the diagnosis. He was promptly started on 200mg of oral doxycycline.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eGiven his respiratory distress, the initial differentials included scrub typhus myocarditis with cardiogenic pulmonary edema and scrub typhus pneumonitis. A bedside ultrasound scan of the chest revealed bilateral mild pleural effusions with significant B-lines, suggesting pulmonary interstitial involvement, but there was no consolidation. Bedside echocardiography performed by the emergency team revealed mild global hypokinesia, whereas electrocardiogram revealed sinus tachycardia without abnormal T or ST changes or arrhythmias (Figure-2). His chest X-ray revealed upward diversion of pulmonary vessels, and bilateral pulmonary hilar congestion with a bat-wing appearance, suggesting pulmonary edema (Figure-3-A). A working diagnosis of scrub typhus-associated myocarditis with pulmonary edema was made, and the patient was given oxygen via a face mask and intravenous frusemide 20 mg. Within three hours, his respiratory distress improved, his SpO₂ increased to 96% on room air, his respiratory rate normalized to 18 breaths/min, and his heart rate decreased to 102 bpm. However, a formal cardiology echocardiogram later revealed normal left ventricular function with no evidence of myocarditis, and troponin levels were within normal limits, making cardiogenic pulmonary edema unlikely. Given his good urine output and normal serum creatinine levels, renal failure as a contributing factor was also ruled out. Although BNP was unavailable, the diagnosis of noncardiogenic pulmonary edema was made on the basis of the remaining clinical evidence. The results of the patient\u0026rsquo;s blood tests are summarized in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eSummary of the laboratory test results of the patient.\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"3\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLaboratory test\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eResult\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eNormal range\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eWhite cell count\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e4.07 \u0026times; 10\u003csup\u003e9\u003c/sup\u003e/L\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e4.0\u0026ndash;10.0 \u0026times; 10\u003csup\u003e9\u003c/sup\u003e/L\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHemoglobin\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e12.1 g/dL\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e12\u0026ndash;15 g/dL\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePlatelets\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e76 \u0026times; 10\u003csup\u003e9\u003c/sup\u003e/L\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e150\u0026ndash;400 \u0026times; 10\u003csup\u003e9\u003c/sup\u003e/L\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eC-Reactive protein\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e91 mg/L\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0\u0026ndash;3 mg/L\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAspartate transferase\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e95.5 U/L\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e15\u0026ndash;37 U/L\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAlanine aminotransferase\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e119.4 U/L\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e16\u0026ndash;63 U/L\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSodium\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e137 mmol/L\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e136\u0026ndash;145 mmol/L\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePotassium\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e3.94 mmol/L\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e3.5\u0026ndash;5.1 mmol/L\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCreatinine\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.81 mg/dL\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.7\u0026ndash;1.3 mg/dL\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eUrea\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e23.3 mg/dL\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e18\u0026ndash;55 mg/dL\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eProthrombin time\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e13.4 sec\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e11-13.5 sec\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eHis diuretic therapy was continued for 48 hours before discontinuation. Doxycycline was continued at 200 mg every 12 hours for 48 hours, followed by 100 mg every 12 hours for the next eight days. He was monitored in the ICU for 24 hours before being transferred to the medical ward. His fever resolved within 36 hours of admission. A repeat chest X-ray performed after 48 hours of diuretic therapy showed significant improvement (Figure-3-B). He made an uneventful recovery before being discharged in stable condition. The Weil-Felix test result, which is not immediately available due to processing time, was received two weeks after presentation and revealed a high OXK titer of 1:1280, supporting the diagnosis of scrub typhus.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003e\u003cem\u003eOrientia tsutsugamushi\u003c/em\u003e, is an obligate intracellular gram-negative bacterium transmitted by the bite of infected chigger larvae of \u003cem\u003eLeptotrombidium\u003c/em\u003e mites [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. Following inoculation, the bacteria replicate locally, leading to the development of a papule that subsequently ulcerates and forms a necrotic eschar. One of the earliest and most characteristic clinical signs of scrub typhus is eschar. While its presence is highly suggestive of scrub typhus, it is often overlooked because of its painless nature and hidden locations, such as the groin, axilla, or buttocks, especially in dark-skinned individuals [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. In endemic regions such as Sri Lanka, the identification of an eschar remains vital for early diagnosis, as demonstrated in our case. Eschar is often accompanied by regional lymphadenopathy, which can progress to generalized lymph node enlargement within a few days [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. Humans typically develop an acute febrile illness within 8\u0026ndash;10 days following a chigger bite, with bacteraemia preceding the onset of fever by approximately 1\u0026ndash;3 days [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. Like other rickettsial infections, scrub typhus is characterized by perivascular inflammation affecting small blood vessels. Although endothelial cells are involved, histopathological findings suggest the involvement of macrophages in the disease process [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. Scrub typhus may disseminate into multiple organs through endothelial cells and macrophages, resulting in the development of fatal complications [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eThe presence of pleuropulmonary involvement in patients with scrub typhus has been well documented in the literature. The pathophysiology is thought to involve direct infection of the pulmonary endothelium, immune-mediated injury, and systemic inflammatory responses. However, pulmonary edema in the absence of cardiac or renal dysfunction is exceedingly rare. In our patient, the initial suspicion of myocarditis was based on mild global hypokinesia observed via bedside echocardiography. This was later ruled out by formal echocardiographic assessment, which revealed preserved left ventricular function and normal troponin levels. Renal function was also normal, and urine output remained adequate throughout, excluding volume overload secondary to renal failure. The constellation of findings\u0026mdash;including eschar, serological confirmation, bilateral pulmonary involvement, and absence of cardiac or renal pathology\u0026mdash;strongly supported a diagnosis of scrub typhus\u0026ndash;associated noncardiogenic pulmonary edema due to capillary leak syndrome.\u003c/p\u003e\u003cp\u003eARDS is the most common cause of noncardiogenic pulmonary edema; however, distinguishing it from other forms of noncardiogenic pulmonary edema can be clinically challenging. ARDS is characterized by the acute onset of hypoxemia, bilateral infiltrates on chest imaging, and the absence of left heart failure, often requiring mechanical ventilation. In contrast, although our patient presented with pulmonary congestion on chest radiography and hypoxemia, the clinical course and rapid response to diuretic therapy supported a diagnosis of noncardiogenic pulmonary edema unrelated to ARDS. ARDS typically evolves over days and responds more slowly to treatment. A few cases in the literature describe noncardiogenic pulmonary edema in patients with scrub typhus [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eInterestingly, our patient\u0026rsquo;s respiratory distress improved rapidly following the administration of low-dose intravenous frusemide. Although capillary leak syndrome\u0026ndash;related pulmonary edema is typically noncardiogenic and may not respond well to diuretics, this case highlights that diuretics may provide symptomatic relief in selected, hemodynamically stable patients with evidence of pulmonary congestion. In such situations, the cautious use of low-dose diuretics may help mobilize extravascular lung fluid without compromising intravascular volume status. The prompt clinical improvement in our patient supports this approach, suggesting that even in noncardiogenic pulmonary edema, supportive diuresis may be beneficial in carefully selected cases.\u003c/p\u003e\u003cp\u003eTimely treatment remains the cornerstone of scrub typhus management. Doxycycline is the first-line treatment for scrub typhus and is considered highly effective [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. Azithromycin is an alternative, particularly for patients with contraindications to doxycycline, such as pregnant women or young children [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. Our patient showed a favorable response to doxycycline, with marked clinical improvement within 48 hours, which was consistent with expected treatment outcomes.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eThis case emphasizes the need to maintain a high index of suspicion for scrub typhus in patients presenting with fever and respiratory symptoms, especially in endemic regions. Although pulmonary edema is an uncommon manifestation, it can occur even in the absence of cardiac or renal dysfunction. Recognizing this rare presentation is crucial for timely diagnosis and management. Furthermore, low-dose diuretics may provide symptomatic benefits in carefully selected, hemodynamically stable patients with noncardiogenic pulmonary edema not related to ARDS.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cdiv class=\"DefinitionList\"\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eARDS\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eacute respiratory distress syndrome\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003c/div\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eClinical Trial\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eInformed written consent was obtained from the patient\u0026rsquo;s father for publication of this case report and accompanying images.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe information used in preparing this case report was obtained from the patient\u0026rsquo;s bed head ticket at the District General Hospital Kilinochchi, Sri Lanka. This report does not contain any patient data that could compromise privacy. Relevant data can be made available by the corresponding author upon reasonable request, subject to ethical and institutional guidelines.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that they have no competing interests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis case report did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors Contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eKS contributed substantially to the clinical management, conception and design of the work, acquisition, analysis, and interpretation of data, and drafting and revision of the manuscript.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eNP contributed substantially to the clinical management, conception and design of the work, acquisition, analysis, and interpretation of data, and drafting and revision of the manuscript.\u003c/p\u003e\n\u003cp\u003eAS contributed substantially to the clinical management, conception and design of the work, acquisition, analysis, and interpretation of data, and drafting and revision of the manuscript.\u003c/p\u003e\n\u003cp\u003eAll authors approved the submitted version of the manuscript and agree to be personally accountable for their own contributions and to ensure the accuracy and integrity of the work.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgement\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eKelly DJ, Fuerst PA, Ching WM, Richards AL. Scrub typhus: the geographic distribution of phenotypic and genotypic variants of Orientia tsutsugamushi. Clin Infect Dis. 2009;48:S203\u0026ndash;30. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1086/596576\u003c/span\u003e\u003cspan address=\"10.1086/596576\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eClinical Overview of Scrub Typhus. (2024). \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://www.cdc.gov/typhus/hcp/clinical-overview/clinical-overview-of-scrub-typhus.html\u003c/span\u003e\u003cspan address=\"https://www.cdc.gov/typhus/hcp/clinical-overview/clinical-overview-of-scrub-typhus.html\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e. Accessed: 25/04/2025.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003ePradeepan JA, Ketheesan N, Murugananthan K. Emerging scrub typhus infection in the northern region of Sri Lanka. BMC Res Notes. 2014;7:719. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1186/1756-0500-7-719\u003c/span\u003e\u003cspan address=\"10.1186/1756-0500-7-719\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eDevamani C, Alexander N, Chandramohan D, et al. Incidence of Scrub Typhus in Rural South India. N Engl J Med. 2025;392:1089\u0026ndash;99. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1056/nejmoa2408645\u003c/span\u003e\u003cspan address=\"10.1056/nejmoa2408645\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWiwanitkit S, Wiwanitkit V. Pleuropulmonary scrub typhus: a summary of Thai cases. J Vector Borne Dis. 2012;49:48.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLin SY, Matsuno Y, Yokosawa M, et al. Analysis of scrub typhus involvement of the lung by bronchoalveolar lavage: A case report. Respiratory Invest. 2016;54:487\u0026ndash;9. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.resinv.2016.06.004\u003c/span\u003e\u003cspan address=\"10.1016/j.resinv.2016.06.004\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eScrub Typhus. (2023). \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://emedicine.medscape.com/article/971797-overview#a4\u003c/span\u003e\u003cspan address=\"https://emedicine.medscape.com/article/971797-overview#a4\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e. Accessed: 25/04/2025.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eShirai A, Saunders JP, Dohany AL, Huxsoll DL, Groves MG. Transmission of scrub typhus to human volunteers by laboratory-reared chiggers. Jpn J Med Sci Biol. 1982;35:9\u0026ndash;16. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.7883/yoken1952.35.9\u003c/span\u003e\u003cspan address=\"10.7883/yoken1952.35.9\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSuputtamongkol Y, Suttinont C, Niwatayakul K, et al. Epidemiology and clinical aspects of rickettsioses in Thailand. Ann N Y Acad Sci. 2009;1166:172\u0026ndash;9. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1111/j.1749-6632.2009.04514.x\u003c/span\u003e\u003cspan address=\"10.1111/j.1749-6632.2009.04514.x\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eZhou XL, Ye QL, Chen JQ, Li W, Dong HJ. Manifestation of acute peritonitis and pneumonedema in scrub typhus without eschar: A case report. World J Clin cases. 2021;9:6900\u0026ndash;6. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.12998/wjcc.v9.i23.6900\u003c/span\u003e\u003cspan address=\"10.12998/wjcc.v9.i23.6900\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSong JH, Lee C, Chang WH, et al. Short-course doxycycline treatment versus conventional tetracycline therapy for scrub typhus: a multicenter randomized trial. Clin Infect diseases: official publication Infect Dis Soc Am. 1995;21:506\u0026ndash;10. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1093/clinids/21.3.506\u003c/span\u003e\u003cspan address=\"10.1093/clinids/21.3.506\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKim YS, Lee HJ, Chang M, Son SK, Rhee YE, Shim SK. Scrub typhus during pregnancy and its treatment: a case series and review of the literature. Clin Infect diseases: official publication Infect Dis Soc Am. 2006;75:955\u0026ndash;9. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.4269/ajtmh.2006.75.955\u003c/span\u003e\u003cspan address=\"10.4269/ajtmh.2006.75.955\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"bmc-infectious-diseases","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"infd","sideBox":"Learn more about [BMC Infectious Diseases](http://bmcinfectdis.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/infd","title":"BMC Infectious Diseases","twitterHandle":"#bmcinfectdis","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Scrub typhus, Noncardiogenic pulmonary edema, Rickettsial infection","lastPublishedDoi":"10.21203/rs.3.rs-6910447/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6910447/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground:\u003c/h2\u003e\u003cp\u003eScrub typhus is a mite-borne rickettsial infection endemic to parts of Asia, including Sri Lanka, with a wide range of clinical manifestations.\u003c/p\u003e\u003ch2\u003eCase presentation:\u003c/h2\u003e\u003cp\u003eWe report a rare case of a 16-year-old male who presented with a seven-day febrile illness complicated by hypoxemia and pulmonary congestion. Clinical examination revealed eschar and inguinal lymphadenopathy, leading to a diagnosis of scrub typhus. Despite initial suspicion of myocarditis, cardiac and renal evaluations were normal, and the patient rapidly improved with doxycycline and low-dose frusemide. The clinical course, absence of organ dysfunction, and prompt radiological resolution supported a diagnosis of noncardiogenic pulmonary edema unrelated to ARDS.\u003c/p\u003e\u003ch2\u003eConclusion:\u003c/h2\u003e\u003cp\u003eThis case highlights scrub typhus as a rare cause of pulmonary edema occurring in the absence of cardiac and renal involvement, underscoring the need for clinical awareness in endemic regions.\u003c/p\u003e","manuscriptTitle":"A Case of Acute Pulmonary Edema in Scrub Typhus: A Rare Complication with Normal Cardiac and Renal Function","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-07-09 06:00:53","doi":"10.21203/rs.3.rs-6910447/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-08-11T15:21:26+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-08-03T04:25:58+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-07-28T11:12:03+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-07-25T18:25:28+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"116310446495142738462277989080111819700","date":"2025-07-25T17:15:04+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"31829782628258726189712802410680532737","date":"2025-07-24T17:24:31+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"14860401704122798226432787268214125032","date":"2025-07-22T16:09:56+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-07-19T11:23:43+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"302648769272200409995142921437230206894","date":"2025-07-16T07:25:59+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-07-15T16:30:52+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2025-06-20T06:21:57+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-06-19T02:41:54+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-06-19T02:40:45+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Infectious Diseases","date":"2025-06-17T05:18:44+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-infectious-diseases","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"infd","sideBox":"Learn more about [BMC Infectious Diseases](http://bmcinfectdis.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/infd","title":"BMC Infectious Diseases","twitterHandle":"#bmcinfectdis","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"a79bfb0b-2c1e-494e-9d93-8f4ab7ea832d","owner":[],"postedDate":"July 9th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2025-11-17T15:59:24+00:00","versionOfRecord":{"articleIdentity":"rs-6910447","link":"https://doi.org/10.1186/s12879-025-12008-9","journal":{"identity":"bmc-infectious-diseases","isVorOnly":false,"title":"BMC Infectious Diseases"},"publishedOn":"2025-11-11 15:57:01","publishedOnDateReadable":"November 11th, 2025"},"versionCreatedAt":"2025-07-09 06:00:53","video":"","vorDoi":"10.1186/s12879-025-12008-9","vorDoiUrl":"https://doi.org/10.1186/s12879-025-12008-9","workflowStages":[]},"version":"v1","identity":"rs-6910447","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6910447","identity":"rs-6910447","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}