Academic Journal
Retroperitoneal infection associated with Streptococcus dysgalactiae subsp. equisimilis bacteremia and lower-extremity cellulitis: a case report.
| Title: | Retroperitoneal infection associated with Streptococcus dysgalactiae subsp. equisimilis bacteremia and lower-extremity cellulitis: a case report. |
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| Authors: | Fujisawa T; Department of Emergency and Critical Care Medicine, National Hospital Organization Tokyo Medical Center, Tokyo, Japan. Electronic address: tokuo.fujisawa@icloud.com. |
| Source: | Journal of infection and chemotherapy : official journal of the Japan Society of Chemotherapy [J Infect Chemother] 2026 Oct; Vol. 32 (10), pp. 103039. Date of Electronic Publication: 2026 Jul 22. |
| Publication Type: | Case Reports; Journal Article |
| Language: | English |
| Journal Info: | Publisher: Elsevier Country of Publication: Netherlands NLM ID: 9608375 Publication Model: Print-Electronic Cited Medium: Internet ISSN: 1437-7780 (Electronic) Linking ISSN: 1341321X NLM ISO Abbreviation: J Infect Chemother Subsets: MEDLINE |
| Imprint Name(s): | Publication: 2014- : Amsterdam : Elsevier Original Publication: Tokyo : New York : Published for the Society by Churchill Livingstone, c1995- |
| MeSH Terms: | Cellulitis*/microbiology , Cellulitis*/drug therapy , Cellulitis*/complications , Streptococcus*/isolation & purification , Streptococcal Infections*/microbiology , Streptococcal Infections*/drug therapy , Streptococcal Infections*/diagnosis , Streptococcal Infections*/complications , Bacteremia*/microbiology , Bacteremia*/drug therapy, Retroperitoneal Space/microbiology ; Retroperitoneal Space/diagnostic imaging ; Anti-Bacterial Agents/therapeutic use ; Lower Extremity/microbiology ; Lymphangitis/microbiology ; Humans ; Male ; Aged ; Tomography, X-Ray Computed |
| Abstract: | Streptococcus dysgalactiae subsp. equisimilis (SDSE) is an increasingly recognized β-hemolytic streptococcus causing invasive infections resembling those caused by Streptococcus pyogenes. Although SDSE bacteremia commonly arises from skin and soft tissue infections, retroperitoneal infection has rarely been described. We report SDSE bacteremia with retroperitoneal lymphatic involvement suggesting possible extension from lower-extremity cellulitis. A 70-year-old man with diabetes and alcoholic liver disease presented with fever and difficulty moving and was admitted with septic shock. Initial computed tomography showed retroperitoneal lymphadenopathy, retroperitoneal inflammatory changes, and right inguinal lymphadenopathy, without gastrointestinal perforation, pancreatitis, obstructive uropathy, or abscess. On hospital day 2, right lower-leg cellulitis became evident. Blood cultures grew SDSE expressing Lancefield group A antigen. Follow-up computed tomography on hospital day 7 showed persistent retroperitoneal inflammatory changes, dilated retroperitoneal lymphatic vessels, and a thrombus near the left venous angle. These findings were compatible with retroperitoneal lymphadenitis and lymphangitis with secondary inflammation of the surrounding retroperitoneal tissue. No persistent bacteremia, infective endocarditis, osteoarticular infection, abscess formation, or other uncontrolled metastatic focus was identified. Antimicrobial therapy was discontinued on hospital day 15 after bacteremia clearance and clinical improvement. Anticoagulation was administered for the thrombus near the left venous angle and a subsequently detected pulmonary embolism. At 3 months, the retroperitoneal lesions and thrombi had resolved, and no relapse occurred during 6 months of follow-up. This case suggests that SDSE cellulitis may rarely be associated with retroperitoneal lymphatic involvement. In the absence of abscess formation or persistent metastatic infection, prolonged antimicrobial therapy may not necessarily be required. (Copyright © 2026 Japanese Society of Chemotherapy, Japanese Association for Infectious Diseases, and Japanese Society for Infection Prevention and Control. Published by Elsevier Ltd. All rights reserved.) |
| Competing Interests: | Declaration of competing interests The author declares that there are no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. |
| Contributed Indexing: | Keywords: Cellulitis; Lymphadenitis; Lymphatic dissemination; Retroperitoneal infection; SDSE; Streptococcus dysgalactiae subsp. equisimilis |
| Substance Nomenclature: | 0 (Anti-Bacterial Agents) |
| SCR Organism: | Streptococcus dysgalactiae subsp. equisimilis |
| Entry Date(s): | Date Created: 20260722 Date Completed: 20260904 Latest Revision: 20260904 |
| Update Code: | 20260905 |
| DOI: | 10.1016/j.jiac.2026.103039 |
| PMID: | 42486338 |
| Database: | MEDLINE |
| ISSN: | 1437-7780 |
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| DOI: | 10.1016/j.jiac.2026.103039 |