A rare presentation of spontaneous subcutaneous emphysema following Influenza A virus in a young male – A case report

A rare presentation of spontaneous subcutaneous emphysema following Influenza A virus in a young male – A case report | 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 rare presentation of spontaneous subcutaneous emphysema following Influenza A virus in a young male – A case report S P R V Lakmini, Elambotharan Sarannija, Shehan Silva This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6738517/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Introduction Spontaneous subcutaneous emphysema (SSE) is the leakage of air into the subcutaneous tissue plain in the absence of external trauma caused by rise of alveolar pressure leading to rupture of alveoli. This case highlights a very rare occurrence of SSE in influenza A viral infection Case presentation We report a 16 year old previously healthy man who presented with sudden onset diffuse chest pain after having two days of fever and cough. On examination he had crepitation in neck and upper chest areas without respiratory compromise. Plane radiography demonstrated extensive subcutaneous emphysema in chest and neck and contrast enhanced computer tomography (CECT) of chest demonstrated subcutaneous emphysema (SE) with normal lung parenchyma. Influenza A H1N1 was positive in his throat swab and mycoplasma infection, COVID and pyogenic infection were excluded. He was treated with oseltamivir and supplemental high flow oxygen via nasal cannula and met with full recovery in seven days. Conclusion This rises the importance of actively looking for the evidence of SE in patients with influenza since mere presence of SE rise the possibility of underlying serous conditions such as pneumomediastinum and pneumothorax. Early detection and treatment with supplemental oxygen helps in spontaneous recovery without needing for invasive interventions. spontaneous subcutaneous emphysema influenza A case report Figures Figure 1 Figure 2 Introduction Subcutaneous emphysema (SE) occurs when air infiltrates the dermal layer of the skin. It can indicate the leakage of air which is filled in other body cavities such as pneumomediastinum, pneumoperitoneum, or pneumoretroperitoneum. Air can spread to the head, neck, chest, and abdomen, connecting all anatomical planes depending on the pressure gradients.[ 1 ] When SE follows a surgical procedure, it is termed as surgical emphysema. Spontaneous subcutaneous emphysema (SSE) is generated if the cause remains idiopathic.[ 2 ] This case report highlights a rare instance of SSE following influenza A viral infection. Such occurrence in adults is extremely rare although well known to occur in children in the background of asthma.[ 3 ] Case presentation A 16-year-old previously healthy man presented with a two-day history of fever and cough followed by sudden onset diffuse chest pain. He developed soreness of the throat, loss of appetite fever with chills at the same time. On the second day, the cough intensified, leading to acute and diffuse chest pain and discomfort in the neck, without radiation, sweating, nausea, or vomiting. There was no chest trauma reported. He had no history of bronchial asthma or other chronic lung disease and non-smoker without having significant family history. The patient was conscious and rational although febrile (101°F). He was not dyspnoeic and had a respiratory rate of 16/min with pulse oximetry of 98% on room air. SE was evidenced with widespread palpable crepitus in the neck and upper chest, more posteriorly. The air entry was equal bilaterally with occasional coarse crepitations and extensive rhonchi all over. The blood pressure was 120/80 mmHg with a good volume pulse rate of 84/min. He did not have any neck lumps including a goitre or lymphadenopathy. The rest of the systemic examination was normal. He had an unremarkable haemogram although the CRP was raised. The throat swab for Influenza A viral RT-PCR was positive. COVID-19 infection and mycoplasma were excluded (Table 1 ). The postero-anterior (PA) chest (Fig. 1 a) and anteroposterior (AP) neck radiography (Fig. 1 b) confirmed SE. The flexible endoscopic assessment demonstrated normal vocal cords with symmetrical movements in the absence of stenosis, ulcers, tears or growths within the upper aerodigestive regions. A contrast-enhanced CT chest exhibited SE in the neck and bilateral axillae associated with pneumomediastinum (Fig. 2 ). There were no pulmonary bullae, pneumatocoeles or pneumothoraces, and the lung parenchyma was normal. Diagnosis of SSE following influenza A infection was made. The patient was administered with oxygen via a high-flow nasal cannula, at a rate of 60L/min and FiO2 100%. Oseltamivir 75 mg b.d. was administered along with oral co-amoxiclav and clarithromycin to prevent secondary bacterial infection. The SE resolved spontaneously without invasive interventions and the patient was discharged inpatient care on the seventh day of admission. He was reviewed as an outpatient with resolved symptomatology and clinical subcutaneous emphysema with unremarkable repeat radiography at 1 month. Table 1 Summary of investigations. Investigation Results Normal value WBC 7.6 × 109/L (4–10) x 10 9 /L Neutrophils 4.4 × 109/L (2–7) x 10 9 /L Lymphocytes 2.2 × 109/L (1–3) x 10 9 /L Platelet 298 × 109/L (150–400) x 10 9 /L Hb 14.9g/dl 12–16g/dl CRP 31mg/L < 6 mg/dl ESR 3 mm/1st hr AST 14U/L (< 50) < 50U/l ALT 13U/L (< 50) < 50U/l Serum creatinine 94 µmol/l (74–110)µmol/l Serum sodium 138mmol/l (135–145) 135–146mmol/l Serum potassium 3.5mmol/l (3.5–4.5) 3.5–5.1mmol/l Throat swab for Influenza A and B viral RT-PCR Influenza A H1N1 positive COVID 19 PCR Negative Mycoplasma IgM antibodies Non-reactive Sputum & blood cultures Negative Transthoracic echocardiogram Normal with EF > 60% and normal valves. No structural abnormalities Discussion SE can result from surgical procedures, trauma, or infections, or occur spontaneously. Trauma may be either penetrating or blunt trauma to the chest, resulting in rib fractures, tracheal or oesophageal ruptures, and sinus injuries. [ 1 , 4 ] Trauma to airway mucosa during endotracheal intubation, malfunctioning ventilator circuits, Valsalva manoeuvre, and over-inflation of the endotracheal tube cuff are identified as iatrogenic causes for SE. SSE can arise from processes that acutely raise alveolar pressure, such as labour or excessive coughing in conditions like asthma or cannabis use. It involves the presence of air in the subcutaneous tissue, often accompanied by pneumomediastinum, where air is present in the mediastinum. SE with influenza infections in adults as in our patient is a rare occurrence. Few cases of pneumomediastinum in children during the H1N1 pandemic were reported.[ 3 , 5 ] H1N1 viral infection typically presents with fever, cough, sore throat, rhinorrhoea, arthralgia, and myalgia. Lopez Luis et al described a 60-year-old male presenting with chest pain and neck fullness with a positivity for Influenza A H1N1.[ 6 ] The pneumomediastinum and SSE were resolved subsequently with antiviral and supportive therapy.[ 3 ] Influenza B too can present as spontaneous pneumomediastinum and SE.[ 7 ] The pathophysiology remains the same in most cases even though there are numerous causes for SE. Increased intra-alveolar pressure leads to the rupture of peripheral alveoli, releasing air into the pleural cavity, causing pneumothorax or allowing air to track along the bronchovascular bundle to the mediastinum. Thereafter air can track to the pericardium, peritoneum, and fascial planes of the neck, chest wall, and mammary tissues.[ 2 , 8 ] SE usually presents with sudden onset painless soft tissue swelling mainly involving the upper chest, neck face and periorbital area.[ 2 , 9 ] Additional symptoms may include a painful sore throat, neck stiffness, difficulty swallowing, shortness of breath, wheezing, and abdominal distension. Periorbital oedema can also lead to visual disturbances. In more severe instances, patients may experience cutaneous tension, hoarseness, and even pneumoperitoneum rarely leading to compartment syndrome.[ 10 , 11 ] Physical examination shows crepitations on palpation. In this case, the patient presented with diffuse chest pain and crepitations on palpation without respiratory compromise. Soft tissue imaging of the neck and chest using radiography and CT scans can diagnose and detect the presence of air through facial layers. These imaging techniques are crucial for excluding serious conditions like pneumothorax, air embolism, and cardiac tamponade. CT scans are particularly effective in confirming the diagnosis due to their high sensitivity.[ 12 , 13 ] Spontaneous resolution of SE typically occurs within 2 to 10 days for most cases.[ 14 ] In hospitalized patients, oxygen therapy may be beneficial as it accelerates recovery by removing nitrogen from the system.[ 14 ] Complications such as tension pneumothorax and air embolism pose serious risks and require immediate medical attention. There have been instances of vision loss linked to orbital involvement and tracheal compression if the retropharyngeal space is affected.[ 13 ] In this case the patient presented with respiratory symptoms followed by pleuritic chest pain which are common presentations of SE. X rays of chest and neck could confirm SE while CECT chest helped in excluding possibility of underling serious conditions such as pneumomediastinum and pneumothorax. Positivity of throat swab for influenza A directed the etiological diagnosis of SE which is quite rare in the medical literature. Another important aetiology for SE, COVID 19 was excluded by negativity of COVID PCR. Along with this acute mycoplasma infection was excluded by absence of IgM antibodies to Mycoplasma pneumonia , and pulmonary tuberculosis by negative sputum geneXpert and absence of typical radiological findings. Early diagnosis and correct treatment prevented arise of serious complications and ensured patient’s full recovery. Successful treatment with high flow nasal oxygen add on to the medical literature emphasizing its use in treating SE. Conclusion Viral lower respiratory tract infections such as Influenza can rarely complicate with subcutaneous emphysema due to rupture of peripheral alveoli. Although it is a self-limiting disease, rarely it can be complicated with pneumothorax and compartment syndrome. Diagnosis is made on clinical presentation and examination with confirmation done by simple radiography and CECT of the chest. Supplemental oxygen therapy remains the mainstay of treatment in SE and usually with spontaneous recovery in 10–12 days. This case report highlights the importance of identifying SE to prevent complications especially in influenza. Furthermore identifying SE requires consideration of imaging when extra-alveolar air is present. Declarations Funding – Not applicable Conflicts of interest/Competing interest – author declare no conflicts of interest/competing interest. Ethical approval – Not applicable Consent to participate – Informed written consent was obtained from the patient for publication of this case report and accompanying images. Consent for publication - Informed written consent was obtained from the patient for publication of this case report and accompanying images. Availability of data and material – No data were generated or analysed during the current study. Code availability – Not applicable Authors contribution Lakmini S P R V – an internal medicine trainee was involved in the management of the patient and drafted the manuscript. Elambotharan Sarannija – as a senior registrar in internal medicine was involved in the management of the patient. Shehan Silva – as the primary Consultant involved in diagnosing and management of the patient at all steps and along with Lakmini S P R V provided supervision and guidance to write/review the main manuscript. References Maunder RJ, Pierson DJ, Hudson LD. Subcutaneous and mediastinal emphysema. Pathophysiology, diagnosis, and management. Arch Intern Med 1984;144:1447–53. Karadakhy KA, Kakamad FH, Mohammed SH, Salih AM, Ali RK, Kakamad SH, et al. Recurrent spontaneous subcutaneous emphysema of unknown origin: A case report with literature review. Annals of Medicine & Surgery 2022;76. https://doi.org/10.1016/j.amsu.2022.103443. Udupa S, Hameed T, Kovesi T. Pneumomediastinum and subcutaneous emphysema associated with pandemic (H1N1) influenza in three children. Can Med Assoc J 2011;183:220–2. https://doi.org/10.1503/cmaj.100099. Kukuruza K, Aboeed A. Subcutaneous Emphysema. 2024. Hasegawa M, Hashimoto K, Morozumi M, Ubukata K, Takahashi T, Inamo Y. Spontaneous pneumomediastinum complicating pneumonia in children infected with the 2009 pandemic influenza A (HINI) virus. Clinical Microbiology and Infection 2010;16:195–9. https://doi.org/10.1111/j.1469-0691.2009.03086.x. Luis BAL, Navarro AO, Palacios GMR. Pneumomediastinum and subcutaneous emphysema associated with influenza A H1N1 virus. Lancet Infect Dis 2017;17:671. https://doi.org/10.1016/S1473-3099(17)30262-1. Alnofal WY, Alshadely MR, Khatib MA. Spontaneous Subcutaneous Emphysema and Pneumomediastinum Associated With Influenza B Virus in a Young Male Adult: A Case Report. Cureus 2021. https://doi.org/10.7759/cureus.13077. Perraut M, Gilday D, Reed G. Traumatic occurrence of chest wall tamponade secondary to subcutaneous emphysema. CJEM 2008;10:387–91. https://doi.org/10.1017/S1481803500010435. Gajardo R.M.A., Gajardo R.P.E., Zuniga T.C.G., Sepulveda P.D., Lopez C.A., Roa H.I.J., et al. Subcutaneous Emphysema after Ultrasonic Treatment: A Case Report. Int J Odontostomat 2009;3:67–70. Aghajanzadeh M, Dehnadi A, Ebrahimi H, Fallah Karkan M, Khajeh Jahromi S, Amir Maafi A, et al. Classification and Management of Subcutaneous Emphysema: a 10-Year Experience. Indian Journal of Surgery 2015;77:673–7. https://doi.org/10.1007/s12262-013-0975-4. Beck PL, Heitman SJ, Mody CH. Simple Construction of a Subcutaneous Catheter for Treatment of Severe Subcutaneous Emphysema. Chest 2002;121:647–9. https://doi.org/10.1378/chest.121.2.647. Cuccia A, Geraci A. Cervicofacial and mediastinal emphysema after dental extraction. Dent Med Probl 2019;56:203–7. https://doi.org/10.17219/dmp/108615. Brito D, Medeiros C, Caley L. Subcutaneous Emphysema after a Dental Procedure. Eur J Case Rep Intern Med 2022. https://doi.org/10.12890/2022_003153. Brzycki R. Case Report: Subcutaneous Emphysema and Pneumomediastinum Following Dental Extraction. Clin Pract Cases Emerg Med 2021;5. https://doi.org/10.5811/cpcem.2020.9.49208. Additional Declarations No competing interests reported. Supplementary Files CAREchecklistSubcutaneousemphysema.pdf Cite Share Download PDF Status: Posted Version 1 posted 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-6738517","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Case Report","associatedPublications":[],"authors":[{"id":467378520,"identity":"84d4ad34-c117-4c58-9d69-b19d45c24164","order_by":0,"name":"S P R V Lakmini","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA7klEQVRIiWNgGAWjYHACNoYEBoZ6+wNA5oMKIMHM3ECUlgQGkJaEMyAtjERoYYBpSWwDsQloMZ+R/OzBwx12eYwNvM8kEufVRvO3A7X8qNiGU4vMjTRzg8QzycXMDOxmEonbjufOOMzYwNhz5jZOLRISOWwSiW3MjG0MbMwGiduO5TYAtQC5BLXUM/aAtcw5ljufSC2HE2cwsDE+SGyoyd1AUAvPM6AX2o4bGzADtSQcO5C7EajlIF6/sCc/k/zZVi1nwN7GcOBDTV3uvPOHDz74UYFbCwIwg8nDYPIAEerhoI4UxaNgFIyCUTBCAABtGVSTnrx6/wAAAABJRU5ErkJggg==","orcid":"","institution":"Colombo South Teaching Hospital","correspondingAuthor":true,"prefix":"","firstName":"S","middleName":"P R V","lastName":"Lakmini","suffix":""},{"id":467378521,"identity":"c3ebe0ed-f7c3-4837-a2dd-43ba7036420c","order_by":1,"name":"Elambotharan Sarannija","email":"","orcid":"","institution":"Colombo South Teaching Hospital","correspondingAuthor":false,"prefix":"","firstName":"Elambotharan","middleName":"","lastName":"Sarannija","suffix":""},{"id":467378522,"identity":"cb3cc251-c273-4906-915c-d40d898476d4","order_by":2,"name":"Shehan Silva","email":"","orcid":"","institution":"Colombo South Teaching Hospital","correspondingAuthor":false,"prefix":"","firstName":"Shehan","middleName":"","lastName":"Silva","suffix":""}],"badges":[],"createdAt":"2025-05-24 10:38:12","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-6738517/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6738517/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":85346831,"identity":"0087fd02-3430-4504-a1fd-a31453c7107f","added_by":"auto","created_at":"2025-06-25 02:14:55","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":419092,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003ea\u003c/strong\u003e) Chest X-ray PA and \u003cstrong\u003eb\u003c/strong\u003e) Neck X-ray AP views demonstrating SE (white arrow)\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-6738517/v1/1fd8a21cae3e36d7c8daa422.png"},{"id":85346832,"identity":"4b34e26c-e13c-44ae-be69-550d180b517c","added_by":"auto","created_at":"2025-06-25 02:14:55","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":440519,"visible":true,"origin":"","legend":"\u003cp\u003eCECT Chest demonstrating SE\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-6738517/v1/9131ebea4704aaa81664fddf.png"},{"id":85348989,"identity":"2f345126-6136-4dac-8c23-0f136ad95e8e","added_by":"auto","created_at":"2025-06-25 02:31:00","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1839958,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6738517/v1/3890b311-4f20-44cc-b945-06d0991dbbbc.pdf"},{"id":85347725,"identity":"f635aa66-fa65-4236-b0da-67d690d05303","added_by":"auto","created_at":"2025-06-25 02:22:55","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":722257,"visible":true,"origin":"","legend":"","description":"","filename":"CAREchecklistSubcutaneousemphysema.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6738517/v1/288b49c8d4fcc2c2e6665a31.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"A rare presentation of spontaneous subcutaneous emphysema following Influenza A virus in a young male – A case report","fulltext":[{"header":"Introduction","content":"\u003cp\u003eSubcutaneous emphysema (SE) occurs when air infiltrates the dermal layer of the skin. It can indicate the leakage of air which is filled in other body cavities such as pneumomediastinum, pneumoperitoneum, or pneumoretroperitoneum. Air can spread to the head, neck, chest, and abdomen, connecting all anatomical planes depending on the pressure gradients.[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e] When SE follows a surgical procedure, it is termed as surgical emphysema. Spontaneous subcutaneous emphysema (SSE) is generated if the cause remains idiopathic.[\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e] This case report highlights a rare instance of SSE following influenza A viral infection. Such occurrence in adults is extremely rare although well known to occur in children in the background of asthma.[\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]\u003c/p\u003e"},{"header":"Case presentation","content":"\u003cp\u003eA 16-year-old previously healthy man presented with a two-day history of fever and cough followed by sudden onset diffuse chest pain. He developed soreness of the throat, loss of appetite fever with chills at the same time. On the second day, the cough intensified, leading to acute and diffuse chest pain and discomfort in the neck, without radiation, sweating, nausea, or vomiting. There was no chest trauma reported. He had no history of bronchial asthma or other chronic lung disease and non-smoker without having significant family history.\u003c/p\u003e \u003cp\u003eThe patient was conscious and rational although febrile (101\u0026deg;F). He was not dyspnoeic and had a respiratory rate of 16/min with pulse oximetry of 98% on room air. SE was evidenced with widespread palpable crepitus in the neck and upper chest, more posteriorly. The air entry was equal bilaterally with occasional coarse crepitations and extensive rhonchi all over. The blood pressure was 120/80 mmHg with a good volume pulse rate of 84/min. He did not have any neck lumps including a goitre or lymphadenopathy. The rest of the systemic examination was normal.\u003c/p\u003e \u003cp\u003eHe had an unremarkable haemogram although the CRP was raised. The throat swab for Influenza A viral RT-PCR was positive. COVID-19 infection and mycoplasma were excluded (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). The postero-anterior (PA) chest (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ea) and anteroposterior (AP) neck radiography (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eb) confirmed SE. The flexible endoscopic assessment demonstrated normal vocal cords with symmetrical movements in the absence of stenosis, ulcers, tears or growths within the upper aerodigestive regions. A contrast-enhanced CT chest exhibited SE in the neck and bilateral axillae associated with pneumomediastinum (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). There were no pulmonary bullae, pneumatocoeles or pneumothoraces, and the lung parenchyma was normal. Diagnosis of SSE following influenza A infection was made. The patient was administered with oxygen via a high-flow nasal cannula, at a rate of 60L/min and FiO2 100%. Oseltamivir 75 mg b.d. was administered along with oral co-amoxiclav and clarithromycin to prevent secondary bacterial infection. The SE resolved spontaneously without invasive interventions and the patient was discharged inpatient care on the seventh day of admission. He was reviewed as an outpatient with resolved symptomatology and clinical subcutaneous emphysema with unremarkable repeat radiography at 1 month.\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 investigations.\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\u003eInvestigation\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eResults\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eNormal value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eWBC\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e7.6 \u0026times; 109/L\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e(4\u0026ndash;10) x 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\u003eNeutrophils\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e4.4 \u0026times; 109/L\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e(2\u0026ndash;7) x 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\u003eLymphocytes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2.2 \u0026times; 109/L\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e(1\u0026ndash;3) x 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\u003ePlatelet\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e298 \u0026times; 109/L\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e(150\u0026ndash;400) x 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\u003eHb\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e14.9g/dl\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e12\u0026ndash;16g/dl\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCRP\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e31mg/L\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;6 mg/dl\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eESR\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3 mm/1st hr\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAST\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e14U/L (\u0026lt;\u0026thinsp;50)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;50U/l\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eALT\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e13U/L (\u0026lt;\u0026thinsp;50)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;50U/l\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSerum creatinine\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e94 \u0026micro;mol/l\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e(74\u0026ndash;110)\u0026micro;mol/l\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSerum sodium\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e138mmol/l (135\u0026ndash;145)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e135\u0026ndash;146mmol/l\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSerum potassium\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3.5mmol/l (3.5\u0026ndash;4.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3.5\u0026ndash;5.1mmol/l\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eThroat swab for Influenza A and B viral RT-PCR\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eInfluenza A H1N1 positive\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCOVID 19 PCR\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNegative\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMycoplasma IgM antibodies\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNon-reactive\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSputum \u0026amp; blood cultures\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNegative\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTransthoracic echocardiogram\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNormal with EF\u0026thinsp;\u0026gt;\u0026thinsp;60% and normal valves. No structural abnormalities\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\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"},{"header":"Discussion","content":"\u003cp\u003eSE can result from surgical procedures, trauma, or infections, or occur spontaneously. Trauma may be either penetrating or blunt trauma to the chest, resulting in rib fractures, tracheal or oesophageal ruptures, and sinus injuries. [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e] Trauma to airway mucosa during endotracheal intubation, malfunctioning ventilator circuits, Valsalva manoeuvre, and over-inflation of the endotracheal tube cuff are identified as iatrogenic causes for SE. SSE can arise from processes that acutely raise alveolar pressure, such as labour or excessive coughing in conditions like asthma or cannabis use. It involves the presence of air in the subcutaneous tissue, often accompanied by pneumomediastinum, where air is present in the mediastinum.\u003c/p\u003e \u003cp\u003eSE with influenza infections in adults as in our patient is a rare occurrence. Few cases of pneumomediastinum in children during the H1N1 pandemic were reported.[\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e] H1N1 viral infection typically presents with fever, cough, sore throat, rhinorrhoea, arthralgia, and myalgia. Lopez Luis et al described a 60-year-old male presenting with chest pain and neck fullness with a positivity for Influenza A H1N1.[\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e] The pneumomediastinum and SSE were resolved subsequently with antiviral and supportive therapy.[\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e] Influenza B too can present as spontaneous pneumomediastinum and SE.[\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]\u003c/p\u003e \u003cp\u003eThe pathophysiology remains the same in most cases even though there are numerous causes for SE. Increased intra-alveolar pressure leads to the rupture of peripheral alveoli, releasing air into the pleural cavity, causing pneumothorax or allowing air to track along the bronchovascular bundle to the mediastinum. Thereafter air can track to the pericardium, peritoneum, and fascial planes of the neck, chest wall, and mammary tissues.[\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]\u003c/p\u003e \u003cp\u003eSE usually presents with sudden onset painless soft tissue swelling mainly involving the upper chest, neck face and periorbital area.[\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e] Additional symptoms may include a painful sore throat, neck stiffness, difficulty swallowing, shortness of breath, wheezing, and abdominal distension. Periorbital oedema can also lead to visual disturbances. In more severe instances, patients may experience cutaneous tension, hoarseness, and even pneumoperitoneum rarely leading to compartment syndrome.[\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e, \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e] Physical examination shows crepitations on palpation. In this case, the patient presented with diffuse chest pain and crepitations on palpation without respiratory compromise.\u003c/p\u003e \u003cp\u003eSoft tissue imaging of the neck and chest using radiography and CT scans can diagnose and detect the presence of air through facial layers. These imaging techniques are crucial for excluding serious conditions like pneumothorax, air embolism, and cardiac tamponade. CT scans are particularly effective in confirming the diagnosis due to their high sensitivity.[\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e, \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]\u003c/p\u003e \u003cp\u003eSpontaneous resolution of SE typically occurs within 2 to 10 days for most cases.[\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e] In hospitalized patients, oxygen therapy may be beneficial as it accelerates recovery by removing nitrogen from the system.[\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e] Complications such as tension pneumothorax and air embolism pose serious risks and require immediate medical attention. There have been instances of vision loss linked to orbital involvement and tracheal compression if the retropharyngeal space is affected.[\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]\u003c/p\u003e \u003cp\u003eIn this case the patient presented with respiratory symptoms followed by pleuritic chest pain which are common presentations of SE. X rays of chest and neck could confirm SE while CECT chest helped in excluding possibility of underling serious conditions such as pneumomediastinum and pneumothorax. Positivity of throat swab for influenza A directed the etiological diagnosis of SE which is quite rare in the medical literature. Another important aetiology for SE, COVID 19 was excluded by negativity of COVID PCR. Along with this acute mycoplasma infection was excluded by absence of IgM antibodies to \u003cem\u003eMycoplasma pneumonia\u003c/em\u003e, and pulmonary tuberculosis by negative sputum geneXpert and absence of typical radiological findings. Early diagnosis and correct treatment prevented arise of serious complications and ensured patient\u0026rsquo;s full recovery. Successful treatment with high flow nasal oxygen add on to the medical literature emphasizing its use in treating SE.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eViral lower respiratory tract infections such as Influenza can rarely complicate with subcutaneous emphysema due to rupture of peripheral alveoli. Although it is a self-limiting disease, rarely it can be complicated with pneumothorax and compartment syndrome. Diagnosis is made on clinical presentation and examination with confirmation done by simple radiography and CECT of the chest. Supplemental oxygen therapy remains the mainstay of treatment in SE and usually with spontaneous recovery in 10\u0026ndash;12 days. This case report highlights the importance of identifying SE to prevent complications especially in influenza. Furthermore identifying SE requires consideration of imaging when extra-alveolar air is present.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e \u0026ndash; Not applicable\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConflicts of interest/Competing interest\u003c/strong\u003e \u0026ndash; author declare no conflicts of interest/competing interest.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthical approval \u0026ndash;\u0026nbsp;\u003c/strong\u003eNot applicable\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent to participate \u0026ndash;\u0026nbsp;\u003c/strong\u003eInformed written consent was obtained from the patient for publication of this case report and accompanying images.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication -\u0026nbsp;\u003c/strong\u003eInformed written consent was obtained from the patient for publication of this case report and accompanying images.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and material \u0026ndash;\u0026nbsp;\u003c/strong\u003eNo data were generated or analysed during the current study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCode availability \u0026ndash;\u0026nbsp;\u003c/strong\u003eNot applicable\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors contribution\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eLakmini S P R V \u0026ndash; an internal medicine trainee was involved in the management of the patient and drafted the manuscript.\u003c/p\u003e\n\u003cp\u003eElambotharan Sarannija \u0026ndash; as a senior registrar in internal medicine was involved in the management of the patient.\u003c/p\u003e\n\u003cp\u003eShehan Silva \u0026ndash; as the primary Consultant involved in diagnosing and management of the patient at all steps and along with Lakmini S P R V provided supervision and guidance to write/review the main manuscript.\u003c/p\u003e\n"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eMaunder RJ, Pierson DJ, Hudson LD. Subcutaneous and mediastinal emphysema. Pathophysiology, diagnosis, and management. Arch Intern Med 1984;144:1447\u0026ndash;53.\u003c/li\u003e\n\u003cli\u003eKaradakhy KA, Kakamad FH, Mohammed SH, Salih AM, Ali RK, Kakamad SH, et al. Recurrent spontaneous subcutaneous emphysema of unknown origin: A case report with literature review. Annals of Medicine \u0026amp; Surgery 2022;76. https://doi.org/10.1016/j.amsu.2022.103443.\u003c/li\u003e\n\u003cli\u003eUdupa S, Hameed T, Kovesi T. Pneumomediastinum and subcutaneous emphysema associated with pandemic (H1N1) influenza in three children. Can Med Assoc J 2011;183:220\u0026ndash;2. https://doi.org/10.1503/cmaj.100099.\u003c/li\u003e\n\u003cli\u003eKukuruza K, Aboeed A. Subcutaneous Emphysema. 2024.\u003c/li\u003e\n\u003cli\u003eHasegawa M, Hashimoto K, Morozumi M, Ubukata K, Takahashi T, Inamo Y. Spontaneous pneumomediastinum complicating pneumonia in children infected with the 2009 pandemic influenza A (HINI) virus. Clinical Microbiology and Infection 2010;16:195\u0026ndash;9. https://doi.org/10.1111/j.1469-0691.2009.03086.x.\u003c/li\u003e\n\u003cli\u003eLuis BAL, Navarro AO, Palacios GMR. Pneumomediastinum and subcutaneous emphysema associated with influenza A H1N1 virus. Lancet Infect Dis 2017;17:671. https://doi.org/10.1016/S1473-3099(17)30262-1.\u003c/li\u003e\n\u003cli\u003eAlnofal WY, Alshadely MR, Khatib MA. Spontaneous Subcutaneous Emphysema and Pneumomediastinum Associated With Influenza B Virus in a Young Male Adult: A Case Report. Cureus 2021. https://doi.org/10.7759/cureus.13077.\u003c/li\u003e\n\u003cli\u003ePerraut M, Gilday D, Reed G. Traumatic occurrence of chest wall tamponade secondary to subcutaneous emphysema. CJEM 2008;10:387\u0026ndash;91. https://doi.org/10.1017/S1481803500010435.\u003c/li\u003e\n\u003cli\u003eGajardo R.M.A., Gajardo R.P.E., Zuniga T.C.G., Sepulveda P.D., Lopez C.A., Roa H.I.J., et al. Subcutaneous Emphysema after Ultrasonic Treatment: A Case Report. Int J Odontostomat 2009;3:67\u0026ndash;70.\u003c/li\u003e\n\u003cli\u003eAghajanzadeh M, Dehnadi A, Ebrahimi H, Fallah Karkan M, Khajeh Jahromi S, Amir Maafi A, et al. Classification and Management of Subcutaneous Emphysema: a 10-Year Experience. Indian Journal of Surgery 2015;77:673\u0026ndash;7. https://doi.org/10.1007/s12262-013-0975-4.\u003c/li\u003e\n\u003cli\u003eBeck PL, Heitman SJ, Mody CH. Simple Construction of a Subcutaneous Catheter for Treatment of Severe Subcutaneous Emphysema. Chest 2002;121:647\u0026ndash;9. https://doi.org/10.1378/chest.121.2.647.\u003c/li\u003e\n\u003cli\u003eCuccia A, Geraci A. Cervicofacial and mediastinal emphysema after dental extraction. Dent Med Probl 2019;56:203\u0026ndash;7. https://doi.org/10.17219/dmp/108615.\u003c/li\u003e\n\u003cli\u003eBrito D, Medeiros C, Caley L. Subcutaneous Emphysema after a Dental Procedure. Eur J Case Rep Intern Med 2022. https://doi.org/10.12890/2022_003153.\u003c/li\u003e\n\u003cli\u003eBrzycki R. Case Report: Subcutaneous Emphysema and Pneumomediastinum Following Dental Extraction. Clin Pract Cases Emerg Med 2021;5. https://doi.org/10.5811/cpcem.2020.9.49208.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"spontaneous subcutaneous emphysema, influenza A, case report","lastPublishedDoi":"10.21203/rs.3.rs-6738517/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6738517/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eIntroduction\u003c/h2\u003e \u003cp\u003eSpontaneous subcutaneous emphysema (SSE) is the leakage of air into the subcutaneous tissue plain in the absence of external trauma caused by rise of alveolar pressure leading to rupture of alveoli. This case highlights a very rare occurrence of SSE in influenza A viral infection\u003c/p\u003e\u003ch2\u003eCase presentation\u003c/h2\u003e \u003cp\u003eWe report a 16 year old previously healthy man who presented with sudden onset diffuse chest pain after having two days of fever and cough. On examination he had crepitation in neck and upper chest areas without respiratory compromise. Plane radiography demonstrated extensive subcutaneous emphysema in chest and neck and contrast enhanced computer tomography (CECT) of chest demonstrated subcutaneous emphysema (SE) with normal lung parenchyma. Influenza A H1N1 was positive in his throat swab and mycoplasma infection, COVID and pyogenic infection were excluded. He was treated with oseltamivir and supplemental high flow oxygen via nasal cannula and met with full recovery in seven days.\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e \u003cp\u003eThis rises the importance of actively looking for the evidence of SE in patients with influenza since mere presence of SE rise the possibility of underlying serous conditions such as pneumomediastinum and pneumothorax. Early detection and treatment with supplemental oxygen helps in spontaneous recovery without needing for invasive interventions.\u003c/p\u003e","manuscriptTitle":"A rare presentation of spontaneous subcutaneous emphysema following Influenza A virus in a young male – A case report","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-06-25 02:14:50","doi":"10.21203/rs.3.rs-6738517/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"f883f380-64ab-40ea-845d-8984d100c454","owner":[],"postedDate":"June 25th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-06-25T02:14:53+00:00","versionOfRecord":[],"versionCreatedAt":"2025-06-25 02:14:50","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-6738517","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6738517","identity":"rs-6738517","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}