Rheumatic fever, which plays a very small role in industrial countries, occurs several weeks after an infection with group A streptococci. The severity depends on the manifestation of the endocarditis.

 

This article is based on the guidelines provided by the AWMF, the Association of the Scientific Medical Societies in Germany.

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Definition of Rheumatic Fever

Rheumatic Fever After an Infection

Rheumatic fever is an inflammatory connective tissue disease due to bacterial toxins after an infection with group A streptococci. It is a non-suppurative sequelae of the infection.

Epidemiology of Rheumatic Fever

Distribution of Rheumatic Fever

Since in industrial countries streptococci infections of the oropharyngeal tract are usually treated with antibiotics (i.e., penicillin) and prevented with timely vaccines that are available, this disease is very rare in these regions.

Contrary to this, in developing countries, where there are high rates of poverty, poor housing and ventilation and lack of enough antibiotics. Bacterial infections with GAS are common leading to many cases of rheumatic fever. Rheumatic fever plays an important role, especially in the age of 5 to 15.

Rheumatic_heart_disease_world_map

Image: “Rheumatic heart disease world map” by Lokal_Profil. License: CC BY-SA 2.5

Etiology of Rheumatic Fever

Causes of Rheumatic Fever

For example, an angina tonsillaris or pharyngitis due to group A beta hemolytic streptococcmay lead to an infection-induced autoimmune reaction, which in turn can cause the rheumatic fever.

Increased prevalence has also been reported in persons with HLA-DR class II alleles (D8/17).

Pathophysiology of Rheumatic Fever

Two main pathogenic mechanisms have been postulated:

  1. Cytotoxic theory where Group A streptococci elaborate cytotoxic streptolysin O and streptolysin S. these antibodies form concentration whose detection is used in disease diagnosis as ASOT titers.
  2. Immunologic theory explains the occurrence of the disease days after the infection. There is molecular mimicry between the M protein on the protosin membrane of GAS with the tropomyosin and myosin of the heart muscles.

Both pathways lead to an antibody-antigen reaction with mediators such as TNF-α, IFN-γ and IL-10 being predominant with a reduction in the inflammatory regulatory cytokine IL-4. The disease leads to a pancarditis that would cause stenosis of the valves 2-10 years after the initial ARF episode.
pathophysiology-of-rheumatic-heart-disease

Clinical Presentation of Rheumatic Fever

Occurrence of Rheumatic Fever

Typically, rheumatic fever occurs two to three weeks after a declined infection. It presents as general symptoms like fever, headaches, and sweating. Also, migrating polyarthritis with swelling and reddening occurs. The heart can also be affected by rheumatic fever. Depending on which structure is affected, the disease can expand to a pancarditis. Subcutaneous rheumatic nodes can be found on the skin.

Brain-MRT-Sydenhams-Chorea

Image: “Clinical and Neuroimaging Findings of Sydenham’s Chorea.” by Ekici A, Yakut A, Yimenicioglu S, Bora Carman K, Saylısoy S. License: CC BY 2.0

A late sequela is Sydenham disease (chorea minor), which can occur months after the infection with the streptococci.

Diagnostics of Rheumatic Fever

Clinical Examination of Rheumatic Fever

The clinical examination shows a friction rub on auscultation and signs of pericardial effusion or heart insufficiency. Also, tachycardia and cardiac dysrhythmia can occur, just like audible cardiac murmurs if cardiac valves are affected.

Laboratory tests may reveal increased inflammatory parameters. Also, streptococci can be detected in the throat swab. Antibodies like antistreptolysin O or anti-desoxyribonuclease B can be determined. If the cardiac valves are affected, this can be detected in echocardiography. The ECG can demonstrate unspecific changes.

ECG-rheumatic-fever

Image: “Adams-Stokes attack as the first symptom of acute rheumatic fever. Electrocardiogram showing complete A-V block with a ventricular rate of 30 bpm.” by Carano N, Bo I, Tchana B, Vecchione E, Fantoni S, Agnetti A. License: CC BY 2.0

Pathology of Rheumatic Fever

Histology of Rheumatic Fever

acute-rheumatic-myocarditis

Image: “Incidental histological diagnosis of acute rheumatic myocarditis” by pina GS, Sampaio RO, Branco CE, Miranda GB, Rosa VE, Tarasoutchi F. License: CC BY 2.0

Histologically, so-called Aschoff bodies (image on the right) can be found, which consist of fibrinoid necroses around which rotund and giant cells have accumulated. Also, Anitschkow’s cells, which are histiocytes with owl-like nucleoli, are typical of rheumatic fever.

Differential Diagnosis of Rheumatic Fever

The rheumatoid arthritis has to be distinguished from rheumatic fever.

Therapyof Rheumatic Fever

Treatment of Rheumatic Fever

Takes a 3-goal approach involving:

  1. Eradication of GAS where both penicillin V and amoxicillinare suitable for treatment. A change tomacrolides is possible if an allergy against penicillin is present.
  2. Symptom relief. For treatment of the inflammation, NSAIDs are
  3. Prophylaxis for rheumatic fever recurrence is done using penicillin or a macrolide depending on the severity as follows
    1. In those with rheumatic fever without carditis for 5 years or up to 21 years whichever is longer.
    2. In those with rheumatic fever and carditis with no residue dysfunction for 10 years or up to 25 years whichever is longer.
    3. In those with residual heart dysfunction for life or up to 40 years.

Review Questions

Answers can be found below the references.

1. Which is usually the cause of rheumatic fever?

  1. A cold.
  2. A previous streptococci infection.
  3. An endocarditis.
  4. A myocarditis.
  5. It develops idiophatically.

2. Which is most likely part of the pathological picture of rheumatic fever?

  1. Osler’s nodes
  2. Microabscesses with bacteria
  3. Aschoff bodies
  4. Serous exudate
  5. Hypereosinophilia

3. Which is the first-choice treatment for rheumatic fever?

  1. Penicillin
  2. Macrolides
  3. Lincosamides
  4. Glycopeptides
  5. Cephalosporins

 

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