Modern Pediatrics. Ukraine. (2025).8(152): 115-119. doi: 10.15574/SP.2025.8(152).115119
Boyarchuk O. R.¹, Yuryk I. E.^2
1I. Horbachevsky Ternopil National Medical University, Ukraine
²Ternopil Regional Children’s Clinical Hospital, Ukraine

For citation: Boyarchuk OR, Yuryk IE. (2025). Acute rheumatic fever or post-streptococcal reactive arthritis? Diagnostic challenges illustrated by a clinical case. Modern Pediatrics. Ukraine. 8(152): 115-119. doi: 10.15574/SP.2025.8(152).115119.
Article received: Oct 14, 2025. Accepted for publication: Dec 15, 2025.

Acute rheumatic fever (ARF) and post-streptococcal reactive arthritis (PSRA) are complications of infection caused by group A β-hemolytic streptococcus. These conditions share similar clinical manifestations but differ substantially in prognosis and treatment strategies. In clinical practice, differential diagnosis remains challenging, particularly in the absence of cardiac involvement or other major Jones criteria for ARF.
Aim – to demonstrate the diagnostic difficulties in distinguishing ARF from PSRA using a clinical case of an adolescent with acute polyarthritis and a pronounced inflammatory response following streptococcal infection.
Clinical case. We analyzed clinical data from a 14-year-old patient, including medical history, physical examination, laboratory parameters, instrumental investigations (еlectrocardiogram, echocardiography, and ultrasound evaluation of joints), and treatment strategy. The patient presented with fever, polyarthritis, a pronounced systemic inflammatory response (high C-reactive protein, elevated erythrocyte sedimentation rate, leukocytosis), and a markedly elevated antistreptolysin-O titer (3200 IU/mL), findings compatible with the Jones criteria for ARF. However, the characteristics of arthritis – non-migratory and prolonged, with a poor response to non-steroidal anti-inflammatory drugs (NSAIDs) and absence of carditis – favored the diagnosis of PSRA. Glucocorticoid therapy was required due to insufficient response to NSAIDs.
Conclusions. This case illustrates the complexity of differentiating PSRA from ARF in the presence of overlapping clinical features and a pronounced inflammatory response. In such situations, dynamic clinical monitoring, assessment of treatment response, and surveillance for potential development of carditis over the following months are essential. Timely diagnosis and appropriate management of streptococcal infections remain the cornerstone of preventing post-streptococcal complications
The study was conducted in accordance with the principles of the Declaration of Helsinki. Informed consent was obtained from the patient and his parents prior to study participation.

The authors declare no conflict of interest.

Keywords: acute rheumatic fever, post-streptococcal reactive arthritis, adolescents, polyarthritis, streptococcal infection, group A β-hemolytic streptococcus, differential diagnosis.

REFERENCES

1. Balan S, Krishna MP, Sasidharan A, Mithun CB. (2025). Acute rheumatic fever and Post-streptococcal reactive arthritis. Best Pract Res Clin Rheumatol. 39(2): 102067. https://doi.org/10.1016/j.berh.2025.102067; PMid:40345912

2. Barash J, Mashiach E, Navon-Elkan P, Berkun Y, Harel L, Tauber T et al. (2008). Differentiation of post-streptococcal reactive arthritis from acute rheumatic fever. J Pediatr. 153(5): 696-699. https://doi.org/10.1016/j.jpeds.2008.05.044; PMid:18657830

3. Bawazir Y, Towheed T, Anastassiades T. (2020). Post-Streptococcal Reactive Arthritis. Curr Rheumatol Rev. 16(1): 2-8. https://doi.org/10.2174/1573397115666190808110337; PMid:31393253

4. Boyarchuk O, Hariyan T, Kovalchuk T. (2018). Clinical features of rheumatic heart disease in children and adults in Western Ukraine. Bangladesh Journal of Medical Science. 18(1): 87-93. https://doi.org/10.3329/bjms.v18i1.39556

5. Boyarchuk O, Mochulska O, Komorovsky R. (2021). Diagnosis and management of pharyngitis in children: a survey study in Ukraine. Germs. 11(3): 363-371. https://doi.org/10.18683/germs.2021.1273; PMid:34722358 PMCid:PMC8548041

6. Boyarchuk O, Predyk L, Yuryk I. (2021). COVID-19 in patients with juvenile idiopathic arthritis: frequency and severity. Reumatologia. 59(3): 197-199. https://doi.org/10.5114/reum.2021.107590; PMid:34538947 PMCid:PMC8436806

7. Boyarchuk OR, Mochulska OM. (2021). Analysis of awareness of practical medicinal doctors on diagnosis and treatment of pharyngitis in children. Modern Pediatrics. Ukraine. 4(116): 29 35. doi 10.15574/SP.2021.116.29.

8. Chun C, Kingsbury DJ. (2019). Poststreptococcal Reactive Arthritis: Diagnostic Challenges. Perm J. 23: 18.304. https://doi.org/10.7812/TPP/18.304; PMid:31926573 PMCid:PMC6836562

9. Gerber MA, Baltimore RS, Eaton CB, Gewitz M, Rowley AH, Shulman ST et al. (2009). Prevention of rheumatic fever and diagnosis and treatment of acute Streptococcal pharyngitis: a scientific statement from the American Heart Association Rheumatic Fever, Endocarditis, and Kawasaki Disease Committee of the Council on Cardiovascular Disease in the Young, the Interdisciplinary Council on Functional Genomics and Translational Biology, and the Interdisciplinary Council on Quality of Care and Outcomes Research: endorsed by the American Academy of Pediatrics. Circulation. 119(11): 1541-1551. https://doi.org/10.1161/CIRCULATIONAHA.109.191959; PMid:19246689

10. Gewitz MH, Baltimore RS, Tani LY, Sable CA, Shulman ST, Carapetis J et al. (2015). Revision of the Jones Criteria for the diagnosis of acute rheumatic fever in the era of Doppler echocardiography: a scientific statement from the American Heart Association. Circulation. 131(20): 1806-1818. Epub 2015 Apr 23. doi: 10.1161/CIR.0000000000000205. Erratum in: Circulation. 2020 Jul 28; 142(4): e65. https://doi.org/10.1161/CIR.0000000000000889

11. Goldberg-Bockhorn E, Hagemann B, Furitsch M, Hoffmann TK. (2024). Invasive Group A Streptococcal Infections in Europe After the COVID-19 Pandemic. Dtsch Arztebl Int. 121(20): 673-680. https://doi.org/10.3238/arztebl.m2024.0127; PMid:38961826 PMCid:PMC11966131

12. Khan M, Furrukh N, Naveed F. (2025). The Next Pandemic? Streptococcal Toxic Shock Syndrome on the Rise. Disaster Med Public Health Prep. 19: e53. https://doi.org/10.1017/dmp.2025.44; PMid:40045491

13. Komorovsky RR, Boyarchuk OR, Synytska VO. (2019). Streptococcus gordonii-associated infective endocarditis in a girl with Barlow's mitral valve disease. Cardiol Young. 29(8): 1099-1100. https://doi.org/10.1017/S1047951119001434; PMid:31280738

14. Mackie SL, Keat A. (2004). Poststreptococcal reactive arthritis: What is it and how do we know? Rheumatology (Oxford). 43: 949-954. https://doi.org/10.1093/rheumatology/keh225; PMid:15150434

15. Nandikol SS, Sharma A, Saxena A, Sonawane V, Jatoo Z. (2025). Differentiating post-streptococcal reactive arthritis from acute rheumatic fever: a case report and review of literature. International Journal of Contemporary Pediatrics. 12(5): 835-838. https://doi.org/10.18203/2349-3291.ijcp20251107

16. Pathak H, Marshall T. (2016). Post-streptococcal reactive arthritis: where are we now. BMJ Case Rep. 2016: bcr2016215552. https://doi.org/10.1136/bcr-2016-215552; PMid:27520996 PMCid:PMC4986150

17. Sato S, Uejima Y, Suganuma E, Takano T, Kawano Y. (2017). A retrospective study: Acute rheumatic fever and post-streptococcal reactive arthritis in Japan. Allergol Int. 66(4): 617-620. https://doi.org/10.1016/j.alit.2017.04.001; PMid:28442182

18. Veiga SR, Marques M, Fonseca J, Ventura H, Marques SJ. (2024). Acute Rheumatic Fever or Post-streptococcal Reactive Arthritis: Two Different Entities. Cureus. 16(10): e72687. https://doi.org/10.7759/cureus.72687

19. Watkins DA, Johnson CO, Colquhoun SM, Karthikeyan G, Beaton A, Bukhman G et al. (2017). Global, Regional, and National Burden of Rheumatic Heart Disease, 1990-2015. N Engl J Med. 377(8): 713-722. https://doi.org/10.1056/NEJMoa1603693; PMid:28834488 PMCid:PMC11093343