Rheumatic fever





Definition

Rheumatic fever (RF) is an illness that arises as a complication of untreated or inadequately treated strep throat infection. Rheumatic fever can seriously damage the valves of the heart.

Description

Throat infection with a member of the Group A streptococcus (strep) bacteria is a common problem among school-aged children. It is easily treated with a 10-day course of antibiotics by mouth. However, when such a throat infection occurs without symptoms, or when a course of medication is not taken for the full ten days, there is a 3 percent chance the person will develop rheumatic fever. Other types of strep infections (such as of the skin) do not put the patient at risk for RF.

Demographics

Children between the ages of five and 15 are most susceptible to strep throat, and therefore most susceptible to rheumatic fever. Other risk factors include poverty, overcrowding (as in military camps), and lack of access to good medical care. Just as strep throat occurs most frequently in fall, winter, and early spring, so does rheumatic fever. Rheumatic fever used to be a leading cause of death and disability in children. Since 1960, it has become much less common in the United States, partially because of increasingly accurate and swift diagnosis of strep throat. It is still a large problem in many developing countries. Moreover, children who have family members who have had rheumatic fever are more likely to get rheumatic fever themselves.

Causes and symptoms

Two different theories exist about how a bacterial throat infection can develop into rheumatic fever. One theory suggests that the bacteria produce some kind of poisonous chemical (toxin). This toxin is sent into circulation throughout the bloodstream, thus affecting other systems of the body.

Research seems to point to a different theory, however. The second theory suggests that the disease is caused by the body's immune system acting inappropriately. The body produces immune cells (called antibodies), that are specifically designed to recognize and destroy invading agent—in this case, streptococcal bacteria. The antibodies are able to recognize the bacteria because the bacteria contain special markers called antigens. Due to a resemblance between Group A streptococcus bacteria's antigens and antigens present on the body's own cells, the antibodies may mistakenly attack the body itself.

It is interesting to note that members of certain families seem to have a greater tendency to develop rheumatic fever than do others. This statistical fact could be related to the above theory, in that these families may have cell antigens that more closely resemble streptococcal antigens than do members of other families.

In addition to fever, in about 75 percent of all cases of RF one of the first symptoms is arthritis. The joints (especially those of the ankles, knees, elbows, and wrists) become red, hot, swollen, shiny, and extraordinarily painful. Unlike many other forms of arthritis, this arthritis may not occur symmetrically (affecting a particular joint on both the right and left sides, simultaneously). The arthritis of RF rarely strikes the fingers, toes, or spine. The joints become so tender that even the touch of bed sheets or clothing is terribly painful.

A particular type of involuntary movement, coupled with emotional instability, occurs in about 10 percent of all RF patients. The patient begins experiencing a change in coordination, often first noted by changes in handwriting. The arms or legs may flail or jerk uncontrollably. The patient seems to develop a low threshold for anger and sadness. This feature of RF is called Sydenham's chorea or St. Vitus' dance.

A number of skin changes are common to RF. A rash called erythema marginatum often develops (especially in those patients who will develop heart problems from their illness), composed of pink splotches that may eventually spread into each other. The rash does not itch. Bumps the size of peas may occur under the skin. These are called subcutaneous nodules. They are hard to the touch, but not painful. These nodules most commonly occur over the knee and elbow joint, as well as over the spine.

The most serious problem occurring in RF is called pancarditis ("pan" means total; "carditis" refers to inflammation of the heart). Pancarditis is an inflammation that affects all aspects of the heart, including the lining of the heart (endocardium), the sac containing the heart (pericardium), and the heart muscle itself (myocardium). About 40 to 80 percent of all RF patients develop pancarditis. This RF complication has the most serious, long-term effects. The valves within the heart (structures that allow the blood to flow only in the correct direction and only at the correct time in the heart's pumping cycle) are frequently damaged during the course of pancarditis. This effect may result in blood that either leaks back in the wrong direction or has a difficult time passing a stiff, poorly moving valve. Either way, damage to a valve can result in the heart having to work very hard in order to move the blood properly. The heart may not be able to "work around" the damaged valve, which may result in a consistently inadequate amount of blood entering the circulation.

When to call the doctor

The doctor should be contacted if the child is displaying any of the signs or symptoms of rheumatic fever. If they are not indications of rheumatic fever, they could be indicative of another disease or disorder. The doctor should also be contacted if the child has had a sore throat and fever for more than 24 hours. The doctor will do a strep test, and if the child does have strep throat the doctor can administer antibiotics that will help prevent rheumatic fever.

Diagnosis

There are no laboratory tests that can determine with complete certainty if a child has rheumatic fever. Some laboratory tests may be used in conjunction with careful examination of the patient to determine if the child has RF. A list of diagnostic criteria has been created. These "Jones Criteria" are divided into major and minor criteria. A patient can be diagnosed with RF if he or she has either two major criteria (conditions) or one major and two minor criteria. In either case, it must also be proved that the individual has had a previous infection with streptococcus.

The major criteria include:

  • carditis
  • arthritis
  • chorea
  • subcutaneous nodules
  • erythema marginatum

The minor criteria include:

  • fever
  • joint pain (without actual arthritis)
  • evidence of electrical changes in the heart (determined by measuring electrical characteristics of the heart's functioning during a test called an electrocardiogram, or EKG)
  • evidence (through a blood test) of the presence in the blood of certain proteins that are produced early in an inflammatory/infectious disease

Tests are also performed to provide evidence of recent infection with group A streptococcal bacteria. A swab of the throat can be taken and smeared on a gel-like substance in a petri dish to see if bacteria will multiply and grow over 24 to 72 hours. These bacteria can then be specially processed and examined under a microscope to identify streptococcal bacteria. Other tests can be performed to see if the patient is producing specific antibodies that are only made in response to a recent strep infection.

Treatment

A 10-day course of penicillin by mouth or a single injection of penicillin G is usually the first line of treatment for RF. If the child does not tolerate or is allergic to penicillin, other antibiotics can be used effectively. These antibiotics are given to help cure a strep infection, if the child still has one. Patients will need to remain on some regular dose of antibiotic to prevent recurrence of RF. This can mean a small daily dose of antibiotic by mouth or an injection every three to four weeks. Some practitioners keep patients on this regimen for five years or until they reach 18 years of age whichever comes first. Other practitioners prefer to continue treating those patients who will be regularly exposed to streptococcal bacteria (teachers, medical workers), as well as those patients with known RF heart disease.

Arthritis quickly improves when the patient is given a preparation containing aspirin or some other anti-inflammatory agent (e.g. ibuprofen). Mild carditis also improves with such anti-inflammatory agents, although more severe cases of carditis require steroid medications. A number of medications are available to treat the involuntary movements of chorea, including diazepam for mild cases and haloperidol for more severe cases.

Prognosis

The long-term prognosis of an RF patient depends primarily on whether he or she develops carditis. This manifestation of RF is the only one that can have permanent effects. Those patients with no or mild carditis have an excellent prognosis. Those with more severe carditis have a risk of heart failure, as well as a risk of future heart problems that may lead to the need for valve replacement surgery. Patients who have had rheumatic fever are at an increased risk of getting it again.

KEY TERMS

Antibody —A special protein made by the body's immune system as a defense against foreign material (bacteria, viruses, etc.) that enters the body. It is uniquely designed to attack and neutralize the specific antigen that triggered the immune response.

Antigen —A substance (usually a protein) identified as foreign by the body's immune system, triggering the release of antibodies as part of the body's immune response.

Arthritis —A painful condition that involves inflammation of one or more joints.

Autoimmune disorder —One of a group of disorders, like rheumatoid arthritis and systemic lupus erythematosus, in which the immune system is overactive and has lost the ability to distinguish between self and non-self. The body's immune cells turn on the body, attacking various tissues and organs.

Chorea —Involuntary movements in which the arms or legs may jerk or flail uncontrollably.

Immune system —The system of specialized organs, lymph nodes, and blood cells throughout the body that work together to defend the body against foreign invaders (bacteria, viruses, fungi, etc.).

Inflammation —Pain, redness, swelling, and heat that develop in response to tissue irritation or injury. It usually is caused by the immune system's response to the body's contact with a foreign substance, such as an allergen or pathogen.

Pancarditis —Inflammation of the lining of the heart, the sac around the heart, and the muscle of the heart.

Prevention

Prevention of the development of RF involves proper diagnosis of initial strep throat infections and adequate treatment within 10 days with an appropriate antibiotic. Prevention of RF recurrence requires continued antibiotic treatment, perhaps for life. Prevention of complications of already-existing RF heart disease requires that the patient always take a special course of antibiotics when he or she undergoes any kind of procedure (even dental cleanings) that might allow bacteria to gain access to the bloodstream.

Parental concerns

Rheumatic fever can be life-threatening if not treated. It can also lead to lifelong heart problems. The best way for parents to prevent rheumatic fever is to take seriously sore throats that are accompanied with fever and to take the child to a doctor to test for strep throat. Children who have had rheumatic fever need to take extra precautions to ensure they do not have repeat attacks triggered by strep infections.

See also Strep throat .

Resources

BOOKS

Margulies, Phillip. Everything You Need to Know about Rheumatic Fever. New York: Rosen Publishing Group, 2004.

PERIODICALS

Mercadante, Marcos T., et al. "The Psychiatric Symptoms of Rheumatic Fever." American Journal of Psychiatry 157, i.12 (December 2000): 2036.

Steeg, Carl N., et al. "Rheumatic Fever: No Cause for Complacence." Patient Care 34, i.14 (July 30, 2000): 40.

Stollerman, Gene H. "Rheumatic Fever in the 21st Century." Clinical Infectious Diseases 33, no. 16 (September 15, 2001): 806.

ORGANIZATIONS

American Heart Association. 7272 Greenville Ave., Dallas, TX 75231. Web site: http://www.americanheart.org.

Tish Davidson, A.M.
Rosalyn Carson-DeWitt, MD



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