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Rheumatic fever (RF) is an illness characterized by the presence of one or more of the following findings: arthritis, carditis (cardiac inflammation), rash, chorea (abnormal movements), and subcutaneous nodules. The clinical manifestations are a direct consequence of a throat infection caused by the group A beta-hemolytic Streptococcus bacteria, which causes Strep throat. It usually occurs in children between the ages of 5 to 15 years of age and rarely in children less than four. At present, it is considered a rare complication of Strep throat in the US, although it used to be much more common. It is still not known what the mechanism causing disease is, but it is likely to be mediated by the immune system.
Clinical findings of RF are usually (about 50% of cases) preceded by symptoms of Strep throat which can include sore throat, headache, abdominal pain, rash, tender lymph nodes over neck, and fever. The diagnosis should be confirmed with a throat swab testing for Strep. Once the diagnosis of Strep throat is made, treatment for ten days with antibiotics will significantly minimize the risk of developing rheumatic fever. Patients who are not treated and who have a genetic predisposition to developing RF may develop symptoms about two weeks after the throat infection. A sustained fever is usually present. Patients who have mostly joint complaints will have a more acute onset of symptoms compared to those that have more involvement of the heart. The following are the Major Manifestations of RF (also called the Jones criteria).
- Arthritis: this is the most common manifestation of RF occurring in up to 70% of patients. Joint pain can be severe (some children with this type of arthritis may refuse to even let bed sheets cover the affected joint because of the severe pain) and can occur without significant swelling. There are usually numerous joints involved, with the joints of the lower extremities (i.e. knees) most commonly involved. Different joints may hurt at different times, but pain in one joint rarely lasts for more than several weeks, and this is why it is described as a migratory polyarthritis. The pain is usually easily controlled with anti-inflammatory medications. Chronic joint disease does not usually develop.
- Carditis: the inflammation of the heart is the most serious manifestation of RF occurring in almost half of patients. It occurs more commonly in younger patients. RF can cause inflammation in all the different parts of the heart including the valves, muscle (myocarditis), and outer covering of the heart (pericarditis). Signs of carditis include abnormal heart rhythms, increased heart rate, abnormal electrocardiogram (prolonged PR interval), or chest pain. An echocardiogram may be necessary to determine whether there is involvement of the heart. New murmurs are usually a sign of disease in the valves of the heart, most commonly the mitral valve. This can also be further investigated by an echocardiogram. The most serious complication of heart involvement is congestive heart failure, where the heart fails to pump out enough blood to keep up with the bodies needs. It is imperative that a cardiologist evaluates a child diagnosed with RF who has any symptoms of heart disease.
- Sydenham's Chorea (St. Vitus's dance) are involuntary movements, most commonly involving the hands and face, including the tongue and making speech incoherent. It only occurs in 15% of patients. The patient cannot completely stop the movements voluntarily but movements do stop during sleep. There is usually an associated emotional liability. Chorea may appear up to three months after the initial throat infection and may persist from weeks to months.
- Subcutaneous nodules are small (less than 1 cm) bumps, found mostly over bony areas, usually seen in recurrent attacks, and have an incidence of about 3-10%. Patients who have nodules usually also have severe heart disease. Nodules usually disappear in 1-2 weeks.
- Erythema Marginatum is a red rash that appears usually on the trunk and spreads outward with resolution of the central area. It is transient and is usually associated with heart disease.
Other less specific symptoms and signs (also known as Minor Manifestations of the Jones criteria) include: fever, joint pain without any signs of inflammation (arthralgia), abnormal electrocardiogram (prolonged PR interval), and increased ESR or CRP (measures of inflammation in the blood).
Diagnosis of RF using the Jones criteria requires the presence of two of the major manifestations listed above or one major manifestation and two of the minor manifestations. It is also essential to find proof of streptococcal infection. This can be done with throat cultures or rapid strep tests during the actual throat infection. These may be normal in certain patients, especially if antibiotics were taken prior to testing. Other blood tests can be done to check the immune response of the body. There is usually a fourfold increase in the antibodies against strep. These tests are ASO (increased in 80%) and Streptozyme (increased in 95%).
Since there are no tests that can definitively diagnosis RF, the diagnosis can sometimes be difficult. RF can also easily be confused with other causes of arthritis, especially Juvenile Rheumatoid Arthritis.
Treatment of RF depends on which symptoms are present. All patients should be treated with a ten day course of penicillin (or alternative antibiotic if allergic to penicillin). Fever and joint pain/swelling are usually treated with aspirin or another non-steroidal anti-inflammatory drugs (such as ibuprofen). There is usually a rapid resolution of joint pain within one to two days of starting an anti-inflammatory medicine. Chorea is treated with bed rest and avoidance of stress. At times, this may require medications to sedate the patient including Phenobarbital, haloperidol, Valium. Patients who have heart disease should always inform their doctor of their past condition and take antibiotics prior to any surgical or dental procedures. Once diagnosed with RF, a patient should be on low dose antibiotics to prevent further infections from strep, which may cause a recurrence of symptoms. This is accomplished by a shot of penicillin every 3-4 weeks or bi-daily penicillin tablets. Other antibiotics are substituted in allergic patients. Antibiotics should be continued at least in adulthood and for life and patients with more severe disease.
Prognosis of ARF is mainly dependent on the extent of heart disease. Initial mortality in the US is low (less than 1%). Long-term studies have found mortality 10 years post ARF at 5-10%. Unfortunately, heart disease seems to be the most common manifestation of RF and the only one to cause chronic symptoms or mortality.
RF Recommended Reading List:
In association with amazon.com, these books can help you to learn more and become better educated about your child's condition, its treatment and preventing complications.
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