Acute Rheumatic Fever or Post-streptococcal Reactive Arthritis: Two Different Entities.

The authors present the case of a 71-year-old man with fever, polyarthralgia, and migratory arthritis after the diagnosis of pharyngitis one week earlier. The patient showed unequivocal evidence of recent group A streptococcal (GAS) infection with a significantly elevated antistreptolysin O (ASO) titer that normalized during follow-up. The symptoms, laboratory results, and clinical examination raised uncertainty about whether the patient was suffering from acute rheumatic fever (ARF) or post-streptococcal reactive arthritis (PSReA), as the patient exhibited characteristics of both conditions. These two conditions share a similar origin and, in some cases, lack clear distinction, suggesting that they may be part of the same disease spectrum. The case emphasizes the importance of considering ARF in patients with suspected recent streptococcal infections who present with polyarthralgia and fever, ensuring early and appropriate treatment to prevent complications.