Causes

What causes acute articular rheumatism?*

The main cause for this disease is the beta-haemolytic Streptococcus of group A, which is found in common infectious sites such as the mouth; in dental granulomas, dental abscesses, paradontosis, and other infections such as chronic tonsillitis.

The streptococcal theory is based on:

  1. Bacteriological data. Beta-haemolytic Streptococcus was isolated from extracting material from sites of infection.

  1. Immunological data. Streptococcus bears extracellular and intracellular antigens. Extracellular antigens include streptolysin, which is a protein that increases in levels during rheumatism, streptokinase which is a phosphorylating enzyme, streptodornase, hyaluronidase, which is another enzyme found in elevated levels in patients suffering from rheumatism. Intracellular antigens include: polysaccharides, protein M.

  1. Epidemiological data. It has been noticed that an increase in patients suffering from chronic tonsillitis is correlated with an increase in patients suffering from acute articular rheumatism.

  1. Therapeutic data. Using antibiotics to treat streptococcal angina or using antibiotics with slow release into the bloodstream leads to a decrease of cases of rheumatism.

Other causes*

There are several theories:

  1. Allergy theory. During repeated events of streptococcal infections, the toxins released from the pathogen lead the organism to become hypersensitive. This is why the organism would then mount an immune allergic response. From entry of the pathogen into the organism until the onset of rheumatism, a latent period must first progress. During the latent period, the organism will produce antibodies against streptococcal antigens.

  1. Autoagression theory. Streptococcus has a property where they may lend antigenic character to certain tissue, especially the heart and connective tissue. Upon bearing this character, these tissues trigger the production of antibodies which become fixated on the heart and cause a rheumatic inflammatory process.

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Most experts believe rheumatic fever is caused by the immune system overreacting to the presence of group A streptococcus bacteria.

Almost all cases develop a few weeks after a Streptococcal infections with group Astreptococcus bacteria.

Duringthis throat infection, the lining ofthe throat becomes inflamed asthe immune system responds to the infection.

In rheumatic fever, the process of inflammation seems to spread through the body in an uncontrolled way. The inflammation can affect the:

  • heart, which causes the symptoms of chest pain , fatigue and shortness of breath
  • joints, which causes the symptoms of arthritis
  • skin, which causes the skin rash and nodules to develop
  • nervous system, which causes the symptoms of chorea (uncontrollable jerking) and the changes in personality associated with rheumatic fever

It's not known why the immune system suddenly stops working properly. One theory is that the streptococcal bacteria have a similar molecular structure to certain tissues in the body. The immune system targets not only thebacteria, but also tissues that share a similar molecular structure.

Another theory is that some people may be born with certain genetic traits that make their immune system more likely to malfunction after a throat infection.

*Sections provided by medical author Diana Hysi, MD.

Content supplied by the NHS Website

Medically Reviewed by a doctor on 28 Nov 2016