Rheumatic fever, commonly known as rheumatism in the blood, is a complication that can occur after a picture of pharyngitis caused by the bacterium Streptococcus.
In less developed regions of the world, an estimated 20 million people are suffering from rheumatic fever, which is the leading cause of cardiac death in the population under 50 years. It is a disease that occurs mainly in the young population, with a peak incidence between 5 and 15 years of age. Rheumatic fever is uncommon in adults.
In this article we will explain what is rheumatic fever (rheumatism in the blood), what are its symptoms, its causes and the treatment and prevention options.
Rheumatic fever is an inflammatory disease that attacks the heart and its valves leading to its progressive destruction. It is a complication of common throat infections, such as strep throat and scarlet fever, or skin, such as impetigo caused by Streptococcus pyogenes (Streptococcus b-hemolytic group A from Lancefield).
The story goes like this: a young person gets a common pharyngitis or tonsillitis, of those with fever, sore throat and pus in the tonsils. This patient ends up not seeking medical attention and does not receive antibiotic treatment, as would be expected. As the days go by your immune system will eventually control the infection and pharyngitis may disappear. However, the bacteria Streptococcus pyogenes has a protein very similar to that found in some tissues of our body such as heart valves, joints, nervous system and skin. It so happens that in trying to control the infection, our immune system can end up producing antibodies against this protein that, in addition to attacking the bacterium, also ends up unduly attacking all these other tissues, leading to their destruction.
Rheumatic fever usually arises after 1 to 4 weeks from the onset of throat infection by Streptococcus pyogenes.
Before we move on, some caveats are important:
Not all untreated pharyngitis will present rheumatic fever as a complication. Various germs can cause sore throats, including various types of bacteria and viruses. Rheumatic fever is caused only by Streptococcus pyogenes.
Among the Streptococcus species there are several types of bacteria such as Streptococcus pneumoniae, which causes pneumonia, the group Streptococcus viridans, which causes endocarditis and others. Even among Streptococcus pyogenes, there are several different strains and not all seem to be able to cause rheumatic fever.
In addition to the specific bacteria, a genetic predisposition of the patients to develop rheumatic fever also seems necessary.
Therefore, to have rheumatic fever, it is necessary to have an individual predisposition and throat infection by specific strains of Streptococcus pyogenes. In addition, the patient must not receive adequate antibiotic treatment.
Rheumatic fever usually occurs with a picture of a high fever that is accompanied by one or more of the following signs and symptoms:
Migratory polyarthritis:Arthritis is a picture of inflammation of the joints like knees, elbows, wrists, ankles, etc. The symptoms consist of swelling, redness, local heat and intense pain. We call polyarthritis when arthritis affects several joints at the same time. The migratory term indicates that it is changing of articulation affected throughout the days.
Rheumatic fever polyarthritis is the most common symptom of the disease and affects 3 out of 4 patients.
Carditis: Rheumatic fever attacks the entire heart, from the pericardium, the surrounding membrane, to the heart muscle (myocardium) itself and the heart valves.
Symptoms of heart involvement include chest pain, especially when you breathe deeply, fatigue from exertion, and especially the onset of a heart murmur, indicating injury to one of your valves.
Injury to the heart valves can be severe enough to cause heart failure.
Carditis is the most serious complication of rheumatic fever and occurs in about 40 to 50% of cases. Carditis and arthritis are usually the first two symptoms of rheumatic fever after fever.
Sydenham chorea: Central nervous system involvement with rheumatic fever causes chorea, a neurological disorder manifested by involuntary movement of the arms, legs and head, muscle weakness and speech disorders. Chorea disappears during sleep.
Sydenham's chorea, also called the St. Vitus dance, is more common in women and may appear only after 8 months of throat infection. It occurs in 5 to 10% of cases of rheumatic fever. It may be the first symptom and in some patients it arises without there being signs associated with carditis or arthritis. The girl in the video above completely regained her coordination after a few months and did not get any sequels.
Subcutaneous nodules: the presence of subcutaneous nodules is another typical manifestation of rheumatic fever.
These nodules are usually painless, hardened, without inflammatory signs, measuring between 0.5 and 2 cm. There may be several, but the average is between 3 and 4 nodules distributed mainly at the elbow, wrists and knees. Usually disappear after 1 month.
It occurs in 10% of cases and only in those who also have carditis. The subcutaneous nodules of rheumatic fever are very similar to those of rheumatoid arthritis.
Erythema marginatus: it is a reddish, evanescent rash that mainly affects the trunk and parts of the limbs. It usually gets more evident in hot temperatures and can last for years, appearing and disappearing over time. It occurs in 5% of cases and, just like the subcutaneous nodules, erythema marginate is also usually associated with carditis.
In most cases of rheumatic fever, the acute episode lasts around 6 weeks. In 90% of the cases, the symptoms disappear in a maximum of 3 months. Sydenham's chorea tends to improve in 3 to 4 months, but some in some patients may take up to 2 years.
The main problem with rheumatic fever is cardiac sequelae. Once the valve is damaged, it will not regenerate. Valvular lesions may lead to heart failure and favor the onset of endocarditis . Often surgery is needed to change the affected heart valve.
Anyone who has ever had an episode of rheumatic fever presents a high risk of withdrawal every time a new pharyngitis arises, and therefore prophylactic antibiotic treatment is necessary (explain below).
An examination that can be made to find out if the patient has had recent contact with the bacterium that causes rheumatic fever is the dosage of antistreptolysin O antibody, also known by the acronym ASO. Elevated ASO values indicate that there has been recent contact with Streptococcus bacteria. ASO begins to rise after 1 week of Streptococcus infection and peaks around the 5th or 6th week, at which time the patient has developed symptoms of rheumatic fever.
The treatment of rheumatic fever relies primarily on its prevention. The treatment of bacterial pharyngitis/tonsillitis with antibiotic practically eliminates the risk of the onset of the disease. The ideal is not to delay the start of treatment for more than 7 days after the onset of symptoms.
Failure to prescribe antibiotics, especially if the patient is young, or discontinuation of the antibiotic schedule before the deadline, even if pharyngitis is gone, are the main risk factors for rheumatic fever.
Once the acute episode of rheumatic fever has already appeared, treatment becomes basically palliative. There is no therapy that prevents the destruction of heart valves. In these cases the conduct consists of the administration of antibiotics to eliminate the Streptococcus of the organism, even if there are no longer symptoms of active pharyngitis and in the administration of anti-inflammatory and aspirin for relief of the symptoms like arthritis and chest pain.
Secondary prevention of rheumatic fever
Secondary prevention is the one we do in patients already had an episode of rheumatic fever. As the risk of a second acute condition is very high, prolonged use of antibiotics up to the age of 21 or up to 5 to 10 years after the last attack is indicated. In patients with cardiac sequelae, with valvular lesion, prophylaxis is indicated up to 40 years of age.
The most commonly used schedule is the injection of benzathine penicillin (benzetacil) every 3 to 4 weeks.
