Rheumatic fever

Rheumatic fever is an inflammatory disease that may develop after a throat infection by the Group A streptococcus bacteria not properly treated. It may produce inflammation in multiple organs such as joints, heart, skin and central nervous system.

It is a rare disease in developed countries, but in poor countries it is the main cause of serious heart damage in children (valvular heart disease).

There is no evidence of the cause why the group A streptococcus bacteria trigger in some patients the rheumatic fever. It is believed that the bacteria own a protein very similar to body tissues. When the immune system tries to attack the bacteria, creating antibodies, they also attack the tissues of the body and produce inflammation.

Only the 3% of the infection by the group A streptococcus bacteria develop to a rheumatic fever.

The main risk factors for developing rheumatic fever are:

• Heredity: Other known cases of rheumatic fever in the family
• Lack of health services to properly treat throat infections
• A mild throat infection or without symptoms where the patient has not visited the doctor
• Overcrowding
• Lack of hygiene

Rheumatic fever is common in children between 5 and 15 years old but it can be seen also in young people and adults.

The main symptoms, that may differ for each person, usually appears between 1 to 5 weeks after the bacterial infection (3 weeks is the most common), although it may develop up to 6 months later.

The previous infection is not always noted and when the rheumatic fever is considered a possibility is due to serious complications such as chorea (abnormal involuntary movement disorder) or heart murmurs.

The most common symptoms are:

• Fever
• Fatigue
• Shortness of breath
• Chest pain
• Palpitations and/or fast heart rate (tachycardia)
• Joint pain and inflammation (arthritis) that may migrate from one joint to another. It usually affects the large joints such as the ones on the knees, ankles and elbows and may differ on the right and left sides
• Skin rash (erythema marginatum) that come and go
• Subcutaneous or Mynet’s nodules. They are small and painless masses under the skin. They can be found in the hands, feet, elbows, knees and neck
• Uncoordinated jerking movements (also called Sydenham’s chorea, chorea minor or St Vitus’ dance) that are most common in women, affecting mainly the tongue and upper extremities
• Unusual behavior and mood swings

In some cases, the rheumatic fever may lead, in a long term, to a chronic damage of the heart (rheumatic heart disease). It may progress to heart failure, that is a critical state where the heart does not work properly.

The diagnosis of rheumatic fever is not easy, especially when there is no evidence of a previous throat infection. It uses a scale called Jones Criteria that is based on the symptoms and certain test results.

The doctor performs a physical exam and may ask for additional tests such as:

• Blood test to detect antibodies against the bacteria and the degree of inflammation of the tissues.
• Electrocardiogram (ECG), a test to evaluate the electrical activity of the heart to check for heart disease.
• Echocardiogram: Ultrasound test that checks the structures and valves of the heart.
• Chest X-ray to see changes in the heart size.

The treatment is based on different drugs:

• Antibiotics (penicillin): They attack the bacteria in the acute outbreak and prevent future outbreaks. The preventive treatment to avoid a new bout of rheumatic fever should be done until puberty and should last at least 5 years. The time of the treatment depends on the patient and sometimes it should be for life, for example in people who have suffered from previous rheumatic heart disease.
• Anti-inflammatory drugs (aspirin and corticosteroids): They are used against inflammation, pain and fever.
• Anticonvulsant in case of uncoordinated jerking movements.
• Rest while the inflammation is present and in case of problems when doing exercise due to heart failure.

A proper treatment of pharyngitis by Streptococcus Pyogenes bacteria (in the 9 days after the intense sore throat is detected) minimizes the chances of developing rheumatic fever afterwards.