Rheumatic fever is an inflammatory reaction that can develop as a complication of a Group A streptococcal infection, such as strep throat or scarlet fever. It occurs when the infection has been untreated or undertreated.
It most commonly affects boys and girls aged 5 to 15 years, but it can occur in adults and younger children. Neurologic complications seem to be more common in females.
RF can have long-term complications, the most common being rheumatic heart disease (RHD) which develops in 30 to 45 percent of those with RF. Worldwide, RHD is responsible for 230,000 - 500,000 deaths per year.
Before the widespread introduction of antibiotics, RF was a leading cause of acquired heart disease in developed nations, but it is now relatively rare in these countries. Thanks to routine treatment of Strep throat, RF now only occurs in about 0.04-0.06 cases per every 1,000 children in mainland U.S.
RF is caused by a reaction to the bacteria that cause strep throat, so that diagnosis and treatment of this condition can prevent it from developing into RF.
Symptoms of strep throat include:
- sore throat
- swollen, tender lymph nodes
- trouble swallowing
- nausea and vomiting
- red skin rash
- high temperature
- swollen tonsils
- abdominal pain
Signs and symptoms generally develop 2 to 4 weeks after a streptococcal infection.
Some individuals will experience just one or two of the following symptoms, but others may experience most of them:
- rapid heart rate
- decreased ability to exercise
- joint pain and swelling
- splotchy rash
- uncontrollable twitching and movements
Arthritis, or pain and swelling in the joints, affects 75 percent of patients. It normally starts in the larger joints, such as the knees, ankles, wrists, and elbows, before moving to other joints. This inflammation normally resolves within 4-6 weeks, without causing permanent damage.
Inflammation of the heart can lead to chest pain, palpitations, a sensation that the heart is fluttering or pounding hard, panting, and shortness of breath, and fatigue.
On average, around 50 percent of patients develop carditis or valvulitis, a potentially fatal inflammation of the heart that can have serious, long-term effects. Younger children are more susceptible.
Inflammation of the nerves can lead to symptoms of Sydenham's chorea, including:
- chorea, the uncontrollable jerking of knees, elbows, wrists, and ankles
- inappropriate crying or laughing
- irritability and moodiness
- difficulty controlling fine hand movements
- problems with balance
Symptoms usually pass within a few months but can last up to 2 years. They are not normally permanent.
Other symptoms include a red, blotchy, skin rash, which appears in 1 in 10 cases. Less common are nosebleeds, abdominal pain, bumps and lumps, or nodules, under the skin, and a high fever over 102 degrees Fahrenheit.
The inflammation may also lead to headache, sweating, vomiting, and weight loss.
Treatment aims to destroy the bacteria, relieve symptoms, control inflammation, and prevent recurrences of RF.
Antibiotics, such as penicillin, may be given to destroy any remaining strep bacteria in the body. Further antibiotics may be prescribed, to prevent recurrence. This may continue for 5-10 years depending on the age of the person and whether or not the heart is affected.
Long-term, and even lifelong, preventive antibiotics may be necessary to prevent recurring inflammation of the heart.
It is important to remove all traces of streptococcal bacteria, as any remaining bacteria can lead to repeated occurrences of RF and a significantly higher risk of heart damage, which can become permanent.
Anti-inflammatory drugs: Naproxen, for example, may help to reduce pain, inflammation, and fever.
Corticosteroids: Prednisone may be given if the patient does not respond to first-line anti-inflammatory medications, or if there is inflammation of the heart.
Aspirin: This is not usually recommended for children aged under 16 years because of the risk of developing Reye's syndrome, which can cause liver and brain damage, and even death, but an exception is usually made in cases of RA because the benefits are greater than the risks.
Anticonvulsant medications: These can treat severe chorea symptoms. Examples include valproic acid (Depakene or Stavzor), carbamazepine (Carbatrol or Equetro), haloperidol (Haldol) and risperidone (Risperdal).
Anyone who has RF as a child will need to inform their doctor as they get older because heart damage can appear many years later.
The doctor will ask about the patient's symptoms and recent medical history. They will pay particular attention to any recent illness along with the following:
- swelling, pain, and stiffness in the joints
- any jerky, involuntary movements
- a red or pink skin rash
- small nodules or lumps and bumps under the skin, especially on the elbows, ankles, knees, and knuckles
- irregular heart rhythm
Tests may include:
- Electrocardiogram (EKG): An electrical tracing of the heart to detect abnormal heart rhythms suggesting inflammation
- Echocardiography: An ultrasound of the heart to look for inflammation or heart valve damage
- Blood tests
Additional tests can detect specific strep infections.
Symptoms of RF, and specifically inflammation, may persist for weeks, months, or longer, causing long-term problems.
Rheumatic heart disease (RHD) is the most common and most serious complication.
Globally, RHD is estimated to affect more than 15 million people per year and cause more than 230,000 deaths.
The inflammation causes permanent damage to the heart, most commonly the mitral valve, the valve between the upper and lower chambers of the left side of the heart.
This can lead to:
- Valvular stenosis: The valve narrows, causing a drop in blood flow
- Valvular regurgitation: Blood flows in the wrong direction because of a leak
- Heart muscle damage: Inflammation weakens the heart muscle so that the heart cannot pump properly
Other conditions that may develop if there is damage to heart tissue, the mitral valve, or other heart valves include:
- Heart failure: This is a serious condition in which the heart is not pumping blood throughout the body efficiently. This can affect the left side, the right side, or both sides of the heart.
- Atrial fibrillation: An abnormal heart rhythm where the upper chambers of the heart (the atria) do not coordinate with the lower part of the heart (the ventricles). This causes the heart muscle to contract irregularly, excessively fast, or both making its pumping ability inefficient. This abnormal rhythm can also lead to a stroke.
RF is now rare in developed countries, but it remains a risk elsewhere. Researchers continue to seek effective ways to prevent RF and its complications.
However, not all strains of streptococcal bacteria will lead to RF, and not everyone who has a GAS infection will develop RF.
Genetic factors may increase the risk. The chance of having RF appears to be higher if another family member has had it.
The exact link between group A strep infection and RF remains unclear, but scientists believe that it is not the bacteria itself that causes the disease, but rather the immune system's faulty reaction to it.
Strep bacteria have a protein that resembles one found in some body tissues. Immune system cells that would usually target the bacteria may start attacking the body's own tissues instead, as if they are toxins or infectious agents.
In RF, the tissues that they attack are those of the heart, joints, central nervous system (CNS) and skin. These tissues react by becoming inflamed.
If a patient with Strep bacteria takes a complete course of antibiotic treatment, the chances of RF developing are very low.
In 8 out of 10 cases, the signs and symptoms of RF resolve within 12 weeks. Between 30 and 45 percent of people with RF will develop heart problems. Recurrences of rheumatic fever often occur within 5 years.
In the past, RF was a major cause of mortality, but now this is rare in industrialized countries. However, RF is fatal in 1.5 percent of cases worldwide.
Environmental factors, such as overcrowding, poor sanitation, and poor access to healthcare increase the risk of developing RF.
Leaving strep throat or scarlet fever untreated or partially treated by not finishing a complete course of antibiotics increases the risk of RF significantly.