Table of Contents
- Definition of Rheumatic Fever
- Epidemiology of Rheumatic Fever
- Etiology of Rheumatic Fever
- Pathophysiology of Rheumatic Fever
- Clinical Presentation of Rheumatic Fever
- Diagnostics of Rheumatic Fever
- Pathology of Rheumatic Fever
- Differential Diagnosis of Rheumatic Fever
- Therapy of Rheumatic Fever
- Review Questions
This article is based on the guidelines provided by the AWMF, the Association of the Scientific Medical Societies in Germany.
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.
Etiology of Rheumatic Fever
Causes of Rheumatic Fever
For example, an angina tonsillaris or pharyngitis due to group A beta-hemolytic streptococci may 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:
- 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.
- 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.
Clinical Presentation of Rheumatic Fever
Occurrence of Rheumatic Fever
Typically, rheumatic fever occurs two to three weeks after a declined infection. It presents 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.
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.
Pathology of Rheumatic Fever
Histology of Rheumatic Fever
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.
Therapy of Rheumatic Fever
Treatment of Rheumatic Fever
Takes a 3-goal approach involving:
- Eradication of GAS where both penicillin V and amoxicillinare suitable for treatment. A change to macrolides is possible if an allergy against penicillin is present.
- Symptom relief. For the treatment of the inflammation, NSAIDs are
- Prophylaxis for rheumatic fever recurrence is done using penicillin or a macrolide depending on the severity as follows
- In those with rheumatic fever without carditis for 5 years or up to 21 years, whichever is longer.
- In those with rheumatic fever and carditis with no residue dysfunction for 10 years or up to 25 years, whichever is longer.
- In those with residual heart dysfunction for life or up to 40 years.
Answers can be found below the references.
1. Which is usually the cause of rheumatic fever?
- A cold.
- A previous streptococci infection.
- It develops idiophatically.
2. Which is the most likely part of the pathological picture of rheumatic fever?
- Osler’s nodes
- Microabscesses with bacteria
- Aschoff bodies
- Serous exudate
3. Which is the first-choice treatment for rheumatic fever?