Lessons of the month: Reemergence of rheumatic fever after a systemic streptococcal A infection: The role of cardiac MRI on the diagnosis of subclinical rheumatic carditis.

A 42-year-old man presented with fever, sore throat, rash and painful right knee swelling, preceded by self-medication with oral steroids. Blood and knee cultures yielded group A Streptococcus After 2 weeks of intravenous antibiotics and two arthroscopic knee debridements, he continued to experience spiking fevers, and electrocardiographic changes developed. We postulate that the patient suffered from the first presentation of acute rheumatic fever, following an invasive group A bacteraemic streptococcal infection. The possible role of cardiac magnetic resonance imaging in the diagnosis of rheumatic carditis is discussed. © Royal College of Physicians 2020. All rights reserved.