Internal Diseases and Therapy · MU Sofia

42. Rheumatic fever – diagnosis and treatment

Explains how Group A streptococcal pharyngitis can lead to rheumatic fever, outlining the proposed molecular mimicry mechanism and the revised Jones criteria with their major and minor features. Lists the major manifestations such as carditis, polyarthritis, chorea and erythema marginatum, then covers prevention through antibiotic treatment and secondary prophylaxis, plus cardiac management and echo monitoring. Closes with a short list of other post-streptococcal conditions.

Inside: 1 section · 1 labelled picture · 15 flashcards · 4 min

Topic 42 of 139 in the MU Sofia syllabus for Internal Diseases and Therapy (Medicine, Years 4 and 5). The free AceMed note covers it in 1 section, about 569 words (4 min of reading), with 15 flashcards.

In this note

  1. Rheumatic fever - diagnosis and treatment

Rheumatic fever - diagnosis and treatment

Caused by Streptococcus Pyogenes (Group A strep), Group A strep is a beta hemolytic bacteria and contains an M protein on its surface. The M surface is highly antigenic and it is this which activates the production of antibodies. Rheumatic Fever (RF) is a nonsuppurative immunologically mediated disease. It is a delayed sequela of a pharyngeal infection with the group A strep (streptococcal pharyngitis). After the latent period (at least 2-3 weeks) systemic symptoms begin to develop which may include arteritis, carditis, chorea, subcutaneous nodules and erythema marginatum. Around 3% of patients who have strep throat go on to develop full blown rheumatic fever.

RF is most commonly a problem in the developing world, where almost 20 million people are thought to be affected and it is the leading cause of cardiovascular death during the first five decades of life. This is not the case in more developed countries due to the better hygiene and increased use of antibiotics.

The exact pathobiology is incompletely understood, but it looks as if antibodies directed against group A strep antigens cross-react with host antigens (so called molecular mimicry, where an antibody targets similar looking proteins), meaning that the antibodies directed against the bacteria end up damaging the host organism. The antigens that the antibody binds to can be found in the heart, joints, skin and brain.

We can diagnose rheumatic fever based on the revised Jones criteria, the diagnosis can be made when the patient has evidence of a strep infection, such as elevated or rising antistreptolysin O titer or anti-DNAse B, have two of the major criteria or one major criterion plus two minor criteria.

The major criteria (and main symptoms) are:

  • Migratory polyarthritis - migrating inflammation of the large joints, usually starting at the legs and moving upwards
  • Pancarditis - can present as congestive HF, pericarditis with rub or new heart murmur
  • Endocarditis - largely affects the valves, the mitral valve is the most commonly affected valve
  • Myocarditis - inflammation of the myocardium, this is the leading cause of death in rheumatic fever. Aschoff bodies (areas of fibrinoid necrosis) can be find in the cardiac muscle)
  • Pericarditis - can cause pain and friction rub is audible
  • Subcutaneous nodules - painless, firm collections of collagen fibers over bones or tendons (commonly on the back of the wrist, outside below and in front of the knees)

Continue reading free

The whole note is free with an AceMed account, with its 15 flashcards. Premium adds flashcard recall, highlights and Ask AI.

Start freeAlready a member? Open the note